Chocolate Peanut Butter Cake with Salted Caramel Sauce - This delicious sweet treat combines everyone’s favourite flavours into one amazingly tasty and scrumptious looking drip cake. Layers of airy but moist peanut butter sponge are sandwiched between decadent silky chocolate buttercream, and the salted caramel sauce adds the finishing touch.

CHOCOLATE PEANUT BUTTER CAKE WITH SALTED CARAMEL

This delicious sweet treat combines everyone’s favourite flavours into one amazingly tasty and scrumptious looking drip cake. Layers of airy but moist peanut butter sponge are sandwiched between decadent silky chocolate buttercream, and the salted caramel sauce adds the finishing touch. (Note 1)
Course Dessert
Prep Time 1 hour 20 minutes
Cook Time 40 minutes
Total Time 2 hours
Servings 20

Ingredients

For peanut butter sponge cake:

  • 140 g unsalted butter, softened
  • 150 g smooth peanut butter, softened (preferably without added sugar or a lot of salt)
  • 280 g caster sugar
  • 2 tsp vanilla extract
  • 6 large eggs, room temperature
  • 380 g plain flour
  • 2 tsp baking powder
  • 1 tsp bicarbonate of soda
  • pinch of salt
  • 12 tbsp milk, room temperature

For chocolate buttercream:

  • 500 g unsalted butter, softened
  • 500 g icing sugar, sifted
  • 7 tbsp milk, room temperature
  • 120 g cocoa powder, sifted

For salted caramel:

  • 200 g casted sugar
  • 90 g unsalted butter
  • 180 mL double cream
  • 2 tsp sea salt

Instructions

For peanut butter sponge cake:

  1. Preheat oven to 175 ºC (350 ºF) and line a baking tray with greaseproof/baking paper. Use a shallow baking tray (I've used a 10 x 14" rectangular tray 1 inch deep).

  2. Cream together butter, peanut butter, caster sugar and vanilla extract.
  3. Add eggs, one at a time, whisking vigorously after each addition.
  4. Sift together flour, baking powder, bicarbonate of soda and salt.
  5. Add 1/2 of the flour mixture to the butter mixture and mix until well incorporated.
  6. Mix in the milk.
  7. Add the remaining 1/2 of the flour mixture and mix until well incorporated. Be careful not to over-mix (otherwise the sponge can become rubbery).
  8. Transfer 1/2 of the sponge mix into the baking tray, levelling and smoothing out the surface.
  9. Bake at 175 ºC (350 ºF) for about 20 minutes or until golden and a skewer/toothpick comes out clean.

  10. Remove the sponge from the baking tray, re-line the baking tray, and transfer the other 1/2 of the sponge mix into it. Bake as the first sponge.
  11. Leave both sponges to cool completely before assembling the cakes.

For chocolate buttercream:

  1. Using either a hand mixer with whisk attachments, or a stand mixer with a paddle attachment, beat/whisk butter and 1/2 of icing sugar for 5 minutes on medium to high speed (increase the speed slowly to avoid having the kitchen covered in icing sugar).
  2. Add the milk and the other 1/2 of icing sugar. Beat/whisk the mixture on medium to high speed for about 10 minutes until pale an fluffy.
  3. Add the cocoa powder and beat/whisk thoroughly until evenly incorporated.

For salted caramel:

  1. Heat caster sugar in a saucepan over medium heat, stirring constantly with a heat resistant rubber spatula or wooden spoon.
  2. The sugar may form clumps but will eventually melt into a thick golden brown liquid as you continue to stir. Be careful not to burn the caramel.
  3. Once the sugar is completely melted, immediately add the butter. On its addition, the caramel will bubble rapidly – be careful.
  4. Stir the butter into the caramel until it is completely melted, about 2-3 minutes. The butter will tend to separate from the caramel – just stir vigorously.
  5. Very slowly, drizzle in the double cream while stirring. The mixture will rapidly bubble due to the temperature difference and may splatter – be careful.
  6. Allow the mixture to boil for about 1 minute. It will rise in the pan as it boils.
  7. Remove from heat and stir in the salt. Allow to cool down before using.
  8. Any leftover salted caramel sauce (what's that?) keeps well in the fridge for up to 2 weeks.

For assembly:

  1. Trim off the edges of the cooled sponges, and cut each sponge into halves to get 4 pieces of equal dimensions.
  2. Assemble the cake in the order: sponge, buttercream, sponge, buttercream, sponge, buttercream, sponge. (Sorry, that was patronising.)
  3. Frost the outside of the cake with the remaining buttercream, smoothing out the buttercream in the final step. (Note 2)
  4. Allow the cake to cool in the fridge for at least 1 hour before drizzling the salted caramel sauce (this way, you'll have more control over the extent of the drizzle).
  5. Drizzle the cooled frosted cake with the desired amount of salted caramel sauce.
  6. Let the caramel to set (it will thicken somewhat), and – enjoy!
  7. The cake keeps well in a cool place/ in the fridge for about 3 – 4 days (good luck with that).

Recipe Notes

Note 1: In making this cake, I've baked two sponges, each in a 10 x 14" rectangular tray 1 inch deep baking tray. I then trimmed the sponges to get rectangles, which I then halved to get 4 layers. You can just as well bake your sponges in round baking trays. Changing the amount or thickness of the sponge being baked will require you to adjust the baking time somewhat (use the toothpick test to determine when the sponge is baked). Note also that you can either make all the sponge mix at once and bake the two sponges one after the other, or make two separate sponge mixes (so that part of the mix doesn't stand around while the first part bakes).

Note 2: If you notice that the initial coatings of buttercream have a lot of sponge crumbs in them, crumb coat the cake before the final buttercream finish (that is, coat the cake in a this layer of buttercream and put it in the fridge for about an hour to seal the crumbs inside).