I’m almost embarrassed to tell you how long I’ve been meaning to share this caramel mud cake recipe with you for. I’m not sure if I can even say it. Perhaps we’ll just say that it has been quite some time.
There’s actually a bit of a story behind this recipe, but if you’re in a hurry to get to the recipe, then feel free to just scroll right on down. I can’t blame you at all for being desperate for caramel cake right now. I mean, look at it…
For the rest of you who enjoy a bit of cake recipe history…
Once upon a time (a very long time ago) I was visiting my friend Loralee and we were sitting quietly on the couch ignoring each other while we both worked (yeah, we’ll go with “worked”) on our iPads. And I suddenly found myself wondering out loud “What do you reckon white chocolate mud cake would taste like if you caramelised the sugar? Be better than making a caramel mud cake with brown sugar and golden syrup, right?”
A quick Google search came up with a few caramel mud cake recipes, but most of them called for brown sugar and/or golden syrup to get the ‘caramel’ flavour. Even the couple of other caramel cake recipes out there that did actually include some caramelised sugar still put brown sugar or golden syrup in and that just wasn’t doing it for us.
Sure, those ingredients make a really nice butterscotch-flavoured cake, but we wanted, well, pure caramel flavour rather than sugary-molasses-butterscotch flavour.
Next minute, Loralee had dragged me into the kitchen. Wait, is drag too strong a word? It went something along the lines of…
Loralee: “Let’s try it now.”
Me: “What, like right now?”
Loralee: “Yes, now.”
Me: “Ok then.”
Yeah, she basically dragged me. In my defence, she has a very authoritative ‘teacher voice’. Resistance is futile, even if I was in the mood to resist.
I totally wasn’t. Because Caramel Mud Cake. Seriously.
I split my white chocolate mud cake recipe into quarters and we mixed up four different variations, to test what would work best.
It turns out to get the best flavour, you need to caramelise all of the sugar in the recipe. Two of our batches only had half of the sugar caramelised, and most of the participants in our expert tasting panel (any and all members of Loralee’s extended family who happened to drop in during the next couple of days and were subjected to blind taste testing) much preferred the cakes with all of the sugar caramelised.
Once I got home, I tweaked the recipe a bit more, working on getting the perfect crumb texture and sticky caramel-ness. There were a few things that I wasn’t completely happy with, and I knew I wanted it perfect before I posted it. So what followed were a couple of years of testing-and-then-getting-distracted-and-forgetting-about-it. That’s how I roll, y’all.
But it was always there, in the back of my mind. And now I’m finally ready to share it.
During the recipe tweaking process, I discovered that unlike my white chocolate and dark chocolate mud cakes, the caramel mud cake is actually much better when baked without baking strips and a foil lid. One of my initial struggles with the cake texture was that it was coming out kind of spongy – not like a sponge cake, but like an actual sponge.
Eventually, I figured out that putting the foil lid on kind of steams the cake, and it ended up almost like a steamed pudding. Which is cool if you’re after a steamed pudding cake. But I was not. Without the lid and strips, the cake ends up nicely dense and fudgy.
The edges do get slightly firmer than when I use baking strips, but as I trim the edges of all my cakes before I decorate them, I’m ok with that. If you don’t like to trim your cakes much, then a quick brush with some freshly boiled water over the cake when it comes out of the oven will soften the edges.
And one of the very best things about this cake (yes, it can get even better) is that it turns out almost exactly the same when made with regular wheat flour or gluten-free flour.
The cake that I made for these pictures is the gluten-free version, but I give instructions for both in the recipe. I use my own gluten-free flour blend but you can use your own favourite blend if you like. Just check out the notes below the recipe for more info on that.
Check out my gluten free cakes for decorating post for more information on baking gluten free cakes, including some safety tips if you’re baking for someone with Coeliac disease.
This caramel mud cake is perfect for cake decorating, and you can carve both the gluten-y and non-gulten-y versions. I used this recipe a while back to carve a couple of little mandarin cakes to fool my Dad’s workmate and it’s a surprisingly easy cake to work with. If you use different flours to mine and find your cake is a bit soft or isn’t carving easily, then I suggest chilling it for a bit in the fridge to firm it up, and as with all carved cakes I recommend using chocolate ganache to fill and cover the cake, as it is much firmer than buttercream.
As with most mud cakes, this one keeps really well. When stored in an airtight container or once sealed with frosting and/or fondant, it will keep well for up to a week at cool room temperature. Or you can wrap it well and freeze it.
How to Make the Caramel Mud Cake
As I mentioned earlier, the whole reason this cake tastes so amazing is that we’re using real caramel sauce as a base. I know, to some people the idea of making caramel sauce is a little daunting, what with the boiling sugar and the fear of burning either yourself or the caramel.
The best tip I can give you to get over your trepidation is perhaps a little blunt, but also the only way you’re going to get this caramel mud cake in your life (and in your mouth) – just try it. Seriously, the only way to get over a fear of making caramel is to make the caramel. Read through the recipe below and see what you should be looking for, get all your ingredients for the caramel measured and ready to go, and just do it. If you happen to have a candy thermometer, it does make the process a bit easier – it’s not essential, but it does help.
I know I will probably get asked whether you can use a ready-made caramel sauce for this recipe, or use a different caramel recipe, and the short answer is that I wouldn’t recommend it. The sugar in the caramel is the full amount of sugar used in the recipe, so it is a major component of the recipe turning out successfully. Other caramel sauces will have differing amounts of sugar, and possibly other ingredients not used in this recipe. So, you could try experimenting with it if you wanted to, but I recommend just following the recipe as it is written.
So we start with making what is essentially a caramel sauce – caramelised sugar with a little cream added. This is a blurry bastard of a picture, but it will give you an idea of the colour we’re aiming for.
Then you’ll warm the milk and melt the butter into it, and mix that together with the caramel. I know some people will ask why you can’t just add the milk and butter straight into the caramel and melt it that way, and I can tell you from experience, it’s because caramel is fickle AF, and it will split. Adding cold ingredients to caramel is pretty much a handwritten invitation for it to split and turn into an irreparable chunky mess. But by melting the butter into the milk and warming it all up, we skip over that little trap, feeling pretty good about ourselves.
The mixture needs a little time to cool down (caramel is hot, of course) and then you can add in the rest of the ingredients, and get those babies in the oven.
The cakes do crack just a little on the top, but I found that the very small amount of top crust that I needed to remove to level the cake was just enough to cut off those cracks too. Perfect.
How I Decorated My Caramel Mud Cake
Ok so let’s talk quickly about how I decorated this cake. You can go crazy and decorate yours however you like, but if you want to do what I did here, then read on.
I made a batch of my favourite lightly salted caramel sauce, which I used both to flavour my Swiss meringue buttercream and to drizzle a caramel drip down the side of the cake. Because what’s better than caramel? More caramel. You can make the sauce a week or so before you need to use it, if you want to get a head start.
I split my cakes into two layers each, filled them and smooth iced it all with the buttercream (check out my buttercream tutorial if you don’t already have a favourite method of doing this) and then I popped the leftover buttercream into a couple of piping bags, and piped some swirls and stars on the top of the cake. You can use pretty much any star/swirl tips that you liked, but I’ll list the ones I used below in case you want to be my cake twin.
Wilton 1M (large star tip), Wilton 6B (extra large open star tip), 4B (same as the 6B but slightly smaller) – these three all fit a large coupler. Wilton 32 (same/same but even smaller) Ateco 34 (small star tip) – both used with a small coupler. I used two piping bags, and just switched the tips on and off with the couplers.
I piped a few rose swirls with the 1M tip, then filled in the rest of the crescent shape with the rest of the tips, starting with the bigger ones and working my way down, filling in the gaps with the smaller star tips. This is a great technique if you’re not confident in your piping skills, because there is so much going on that no one will notice if something isn’t perfect.
Then I spooned some caramel sauce over the rest of the top of the cake and added a drip down the side. I prefer to use a squeeze bottle to do the drips, but you can use a spoon if you like. I also used the bottle to add a few little dots of caramel sauce onto the piped stars.
One important thing to note about using caramel for a drip is that it will continue to drip down the cake for a lot longer than a ganache drip does. Make sure your cake is chilled, and warm up the caramel just until it is pourable – don’t make it too runny. Try dripping some down the side of a glass to check if it is the right consistency before you add it to the cake.
It’s also best to do the drip on the day that you plan to serve the cake. Trust me on this one – because this cake I’m showing you is not the first cake I made for this post. Nope, I made one before this. I decorated it and starting taking photos, only to lose the last of the natural light for the day (boo, Kiwi winter) and I left the cake ’til the next day to finish taking photos, hoping against hope that the cake would still be presentable the next morning.
“Haha!” laughed the cake gods “we shall not grant her this wish!”, and so it was, that I walked into my studio the next morning to find a puddle of caramel under the cake stand. So much caramel.
Don’t be like me. Pop your caramel drip on within an hour or so of when you plan to serve your cake.
(And then pour some more on the slices of cake, if you’re feeling extra. When it comes to caramel, extra is always better).
- 125ml whipping cream (or heavy cream)
- 400g sugar (caster sugar works best)
- 3 tbsp corn syrup/liquid glucose
- 125ml water
- 1 1/2 tsp salt
- 1 teaspoon vanilla extract
- 375ml milk (full fat milk works best)
- 350g unsalted butter
- 180g white chocolate
- 375g all purpose flour OR gluten free flour blend*
- 2 teaspoons baking powder
- 1/2 teaspoon Xanthan Gum (if making gluten free)
- 3 large eggs
Line the base and sides of two 7” round (at least 3” high) cake pans.
Measure the cream into a microwave safe jug, and microwave until warm (around 30 sec, depending on your microwave power). The temperature isn’t too important, but warming the cream will help it splatter less when you add it to the caramel. Set aside.
Place the sugar, water and corn syrup in a medium saucepan and stir until all the sugar is moistened. Place over medium high heat. As it comes to the boil, use a pastry brush dipped in water to wash down any sugar crystals on the side of the pan.
Increase the heat to high and boil until the syrup turns a light amber colour. Keep an eye on it, you don’t want it so dark that it burns, but it needs a decent amount of colour to have a deep caramel flavour. It should be about 160°C (320°F) on a sugar thermometer.
Remove from the heat and carefully pour in the cream while stirring with a long handled spoon or spatula. Be careful – it will splutter and there will be a lot of steam! Clean the candy thermometer (if using) and clip it back on the pan. Return the caramel to a medium heat and bring back to the boil, stir gently until smooth and it reaches 115°C (240°F). If not using the thermometer, just boil the caramel until it darkens a little more. If at any point you get even a hint of a burning smell, remove it from the heat immediately. Remove from the heat, stir in the salt and vanilla and set aside.
In a large saucepan, heat the milk and butter together, whisking occasionally over a medium heat until the butter is melted.
(Note: once you are comfortable making the caramel, you can have the milk/butter/chocolate mixture heating while you make the caramel. If you’re not comfortable making the caramel then it is better to keep your attention focussed on it without distraction.)
Slowly whisk the caramel into the milk mixture, then add the white chocolate and whisk until melted and combined. Leave to cool until you can comfortably hold your hand against the pan, or your finger in the mixture without it feeling hot. To cool it faster you can transfer the mixture to a large heatproof bowl. To cool it even faster, place the bowl in a sink full of cold water and add a few handfuls of ice to the water.
While you wait, preheat oven to 150° Celsius. Sift together the flour and baking powder (and Xanthan gum, if making gluten free).
When the liquid ingredients have cooled, add the dry ingredients in three additions. Mix with the whisk, but use a folding rather than whipping motion to avoid air bubbles. Don't worry if there are still little lumps of flour.
Whisk the eggs together with a fork and add them to the batter, mixing again with the whisk.
Pour the batter into the prepared pans and bang them gently on the bench to remove any large air bubbles. Bake for 75 - 90 minutes, or until a skewer inserted into the middle of the cake comes out clean. When the skewer comes out clean, insert a thin bladed knife into the middle of the cake. When that comes out clean or with only a few crumbs attached, the cake is done. If you have an instant read probe thermometer, the centre of the cake should be at least 99°C. Mud cakes can be tricky to gauge for done-ness, so these are the best ways to tell for sure.
Allow the cakes to cool for half an hour, then cover the top with foil, securing around the edge of the pan. Leave the cakes in the pan overnight to cool completely and firm up.
If making this cake gluten free, you will need to use an all purpose gluten free flour blend. You can find my gluten free baking flour blend here, this is what I use for all my cakes. If you choose to use a purchased gluten free flour blend, check to see if it contains a gum ingredient (usually xanthan gum, guar gum or vegetable gum) - if it contains one of these then omit the Xanthan gum from the cake recipe.
If you find the cakes are browning too much on the top before they are cooked in the middle, cover the tops with foil for the remaining baking time.
When stored in an airtight container, or once sealed with frosting and/or fondant, it will keep well for at least a week at cool room temperature. For longer storage before decorating you can wrap it well with plastic wrap, pop it in an airtight container and freeze it.
- 210g egg whites (about 7 egg whites, or use pasteurised egg whites)
- 325g sugar (caster or granulated)
- pinch of salt
- 450g unsalted butter
- 1 Tablespoon vanilla extract
- 3/4 cup lightly salted caramel sauce + extra to decorate
- Thoroughly clean the whisk attachment and heatproof bowl of a stand mixer, and wipe with a paper towel dipped in lemon juice or vinegar to remove any traces of grease.
- Combine the egg whites and sugar in the mixer bowl. Place the bowl over a pot of just-simmering water, making sure the water doesn't touch the bottom of the bowl. Stir constantly until the sugar has dissolved and the mixture reaches 71°C/160°F.
- Place the bowl on the mixer and whip on medium speed for one minute, then increase speed to medium-high and beat until the meringue is stiff and glossy. The mixer bowl should be cool to the touch.
- Switch to the paddle attachment, and with the mixer on low speed add the butter a piece at a time until fully incorporated. If the mixture seems to curdle or separate, don’t panic! Just keep the mixer going on low speed until the buttercream becomes silky and smooth.
- Warm the caramel sauce gently in the microwave until just slightly warm and pourable (don't make it hot, or you'll melt your buttercream). Add to the buttercream along with the vanilla extract and beat again to combine.
- Give it a taste, if it could do with more caramel then add a bit more.
- Split your cakes into layers (I split each cake into two layers, so my finished cake had four layers), fill, layer and cover your cake with the buttercream.
- See post for how I used the buttercream to decorate my cake.
If your buttercream does split and is taking a long time to come back together, you can speed the process up. Touch the side of the bowl - if it still feels very warm, then pop the bowl into the fridge for 5-10 minutes, then beat again. Alternatively, if it feels like the mixture is too cold, then place the bowl back over the pan of simmering water for a couple of minutes, just until it begins to melt around the edges of the buttercream, then remove from the heat and beat again.