Gluten Free Espresso Chocolate Cake with Salted Caramel Buttercream

Why You’ll Love This Espresso Chocolate Caramel Cake

​Flavour. This is the best chocolate cake. Not only does it looks beautiful but also really delivers on deep rich intense chocolate flavour. With both cocoa for richness and melted chocolate folded into the batter, the result is true luxury. Buttermilk gives the sponge a gentle tanginess and using oil instead of butter makes the cake light and moist. Espresso powder is also used in the sponge to give a direct coffee hit. It amps up the chocolate flavour and also gives a complex background flavour.

Easy. This sponge is so quick and simple to make. You just need to make up the dry ingredients and wet ingredients in separate bowls then mix in the melted chocolate.

Customisable Gluten-Free Flours. In this recipe we don’t use a generic all-purpose gluten-free flour but rather an easy combination of rice flour, oat flour and tapioca flour. This is a great alternative as each of these flours can be swapped out if allergies come into play which gives you more control and also means no xanthan gum is needed. These flours make a deliciously rich and moist chocolate cake with a good tender crumb and gorgeous flavour.

Swiss Meringue Buttercream. This is the best buttercream to finish this cake, it smooths over the sponge like a dream with a buttery silky texture and is never too sweet despite all that caramel. It is so much easier to whip up than you think and the generous pouring of salted caramel into the finished buttercream amps up the end result to 11 and then some.

Homemade Salted Caramel Sauce. The same caramel is used to flavour the buttercream and for the salted caramel drip on top of the cake.

Ingredients Needed

Dark chocolate. This recipe uses 70% dark chocolate. However, you can use 50-60% chocolate for a softer creamier chocolate flavour.

Rice flour. Use white rice flour here, you want a light delicate flavour. This is a great economical gluten-free flour which works here due to its neutral taste and light texture. Too much rice flour though can get a little gritty so we need to balance it out with another flour. (see below for substitutions if needed)

Oat flour. This wholegrain flour has a mild, buttery flavour and is useful in gluten-free baking for its ability to add moisture and texture to baked goods. It’s used here for fluffiness and flavour. That toasted butterscotch taste is a great backdrop for the recipe. Make sure it is certified gluten-free. (see below for substitutions if needed).

Tapioca flour (tapioca starch). This starchy flour is needed to help with the structure of the cake. It is ideal for binding and also helps keep the cake light and fluffy.

Cocoa powder. Choose a high quality organic brand if possible. This recipe was tested with Dutch-processed cocoa powder (which is the more common type in the UK – but do check the labels) and has a smooth rich chocolatey flavour.

Espresso powder. Brings out the chocolate flavour rather than giving a coffee flavour. It can be omitted if you are not a coffee lover.

Bicarbonate of soda. Also known as baking soda, this is a white crystalline powder that is commonly used as a leavening agent in baking.

Buttermilk. It’s a fermented dairy product with a tangy flavour and is used here to tenderise the crumb, act as a leavening agent, add moisture, and also enhance the flavour. If you can't get hold of buttermilk then you can use whole milk + 1 ½ tablespoons apple cider   vinegar or lemon juice stirred together and allowed to sit for 10 minutes.

Caster sugar. A fine white sugar which gives lightness. You can substitute for granulated white sugar.

Light Soft Brown Sugar. Using brown sugar adds a gentle molasses flavour and moisture to the batter, enhancing the depth of taste and providing a subtle caramel undertone, contributing to a more flavourful and moist cake.

Olive oil. This is my preferred oil in cakes rather than vegetable oil or coconut oil. But to avoid a strong flavour use a flavourless mild and light olive oil.

Eggs. This recipe uses medium size, about 60g each with shell (50g each without shell). These are often classified as large eggs in the US. I recommend weighing your eggs to ensure the correct amount.

Vanilla extract. Use a good quality extract, I like Nielsen Massey.

Salt. I like to use kosher salt in my baking as it has a round gentle flavour. Using salt in your baked goods lifts and sharpens all the other flavours.

Homemade Caramel

Caster sugar. It’s a fine white baking sugar. If you can only get hold of granulated sugar then that is fine to use too, it will take a little longer to melt but that’s no problem.

Double cream. You can substitute for heavy cream.

Butter. Unsalted butter is the best choice here so you can control the salt content at the end of the recipe. Make sure it is at room temperature.

Vanilla extract. Use a good quality extract, I like Nielsen Massey.

Flaky sea salt. I really like to use Maldon Sea Salt for caramel. It has a perfect clean flavour without overpowering the richness of the caramel.

Salted Caramel Swiss Meringue Buttercream

Egg whites. This basic recipe uses 8 egg whites. You can use fresh egg whites by all means and then just freeze the egg yolks for another day or make custard or ice cream. However, I recommend buying a carton of liquid egg whites as it saves wasting the yolks or finding a use for them.

Caster sugar. This is a finely ground white baking sugar common in the UK. If you can only get hold of white granulated sugar then that’s a fine substitute.

Butter. Unsalted is the best choice here so you can control the salt content. Make sure it is at room temperature. This means that you should be able to press into the buttercream easily using your fingertip but reach resistance so your finger doesn’t sink straight through the butter. The right temperature for the butter here is absolutely key. There are tips below if you have a cold kitchen and your butter is staying too firm.

Vanilla extract. It’s essential in buttercream to use a good quality extract since this is a vanilla buttercream and will be the key flavour here. I like Nielsen Massey. You could always use the seeds from a vanilla bean if you like the speckled effect which can look beautiful covering the right cake.

Salt. It’s essential too. The salt will bring out the flavour of your vanilla and add complexity and depth to the buttercream – you will really notice the difference if it’s left out.

Flour Substitutions

I don't recommend using a generic all purpose gluten-free flour for this cake as the results will come out too dry and they often need xanthan gum to work properly. Instead you could use my Homemade Gluten-Free Flour Blend as a replacement for all 3 flours or if you have allergies then I recommend the following swaps:

• Rice flour and oat flour. These wholegrain flours can be swapped for buckwheat flour, teff flour, sorghum flour or tiger nut flour. However I do recommend still keeping a mix of 2 x wholegrain flours to balance out the blend.
• Tapioca flour. This starchy flour can be swapped for cassava flour, sweet rice flour or potato starch.

Salted Caramel Tips

• Have all ingredients to hand as you start the process as you'll need to work quickly once the sugar has melted.
• Ensure butter and cream are at room temperature to prevent sugar seizing.
• Use a heavy-bottomed saucepan for even heat distribution.
• Start with sugar in an even layer for even melting and to prevent sugar crystals.
• Avoid stirring; gently swirl if edges start to burn.
• Watch closely and don’t walk away as caramel can quickly change colour.
• Gradually add salt to taste; start with 1 teaspoon and adjust if needed. Different salts vary in intensity.
• Leave the caramel to cool overnight as you need to use it totally chilled and thickened for the buttercream.

✨If you would like more detailed information on making the Salted Caramel then visit this helpful post on How To Make Salted Caramel which breaks down every step with loads of tips, tricks and a video to ensure a foolproof result.✨

Swiss Meringue Buttercream Tips

• The temperatures here are important. If you have made SMB a few times then you can intuit when the sugar has melted into the egg whites or when the meringue has cooled enough to add the butter. However for newbies a sugar thermometer is invaluable.
• The butter must be at room temperature before you add it. Slightly soft to the touch but not melty.
• If your butter is too cold then just keep on mixing the buttercream once it’s all added, the butter will soon warm and melt into the buttercream. If that doesn’t work then warm slightly over a bowl of boiling water. Once the edges of the buttercream start to soften then start whipping again off the heat.
• If your butter is too warm place in the fridge for 15 minutes to chill then try re-whipping it.
• As you are adding the butter your buttercream will look a bit curdled. This is absolutely normal. Keep on mixing the buttercream and don’t lose faith, it will always come together in the end.
• If your buttercream does not come together and looks too soupy that means your butter was too warm – see above on how to fix.

✨If you are still worried about making the buttercream then visit this helpful post on How To Make Perfect Swiss Meringue Buttercream which breaks down every step with loads of tips, tricks and a video to ensure a foolproof result.✨