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mint chocolate cake

Mint Chocolate Cake (with Vertical Layers!)

Aimee Field
A light chocolate sponge with creamy mint buttercream. This mint chocolate cake is delicious and sure to impress with its vertical layers inside!
Prep Time 1 hour 30 minutes
Cook Time 15 minutes
Cooling/Chilling Time 1 hour 45 minutes
Total Time 3 hours 30 minutes
Course Cakes
Cuisine British
Servings 10 Slices

Ingredients
  

Sponges

  • 8 large eggs
  • 300 g caster sugar
  • 55 g unsalted butter
  • 165 g plain flour
  • 65 g cocoa powder
  • 2 tsp ground coffee
  • 2 tsp baking powder
  • 1 tsp salt
  • 1/2 tsp ground cinnamon
  • 180 ml whole milk
  • 60 ml vegetable oil
  • 1 1/2 tsp vanilla extract
  • icing sugar for sifting on the warm sponges

Buttercream

  • 300 g unsalted butter room temperature
  • 400 g icing sugar
  • 1/2 tsp peppermint extract
  • 3 tbsp whole milk
  • green gel food colouring

Decoration (optional)

  • mint leaves
  • chocolate shavings

Instructions
 

  • For the sponges: Firstly, pre-heat the oven to 175C/155C Fan/Gas Mark 3 and line two 9x13inch tins with baking paper and set aside. (If you don't have two tins, split the recipe in half and make them one at a time).
  • In a large bowl, place the eggs and caster sugar. Then with an electric hand-whisk or a stand-mixer, whisk on a high speed until the mixture triples in volume and is extremely airy. This will take around 8 minutes. Stop the mixer and set the bowl to the side.
  • Melt the butter in a microwave or in a saucepan, and leave to cool a little. Meanwhile, sift the flour, cocoa powder, coffee, baking powder, salt and cinnamon into the whipped egg mixture. Gently, using a spatula fold the mixture until combined and there are no pockets of flour.
  • In a small bowl, pour in the melted and cooled butter, milk, oil and vanilla extract until combined. Then in two increments, fold into the batter until combined. Then evenly divide the batter between the prepared trays and bake for 12-15 minutes until the sponge springs back when gently touched. Try not to overbake, as your sponges will be prone to cracking.
  • Once the sponges are baked, remove them from the oven and sift the icing sugar generously over. Then place either a clean tea towel or baking paper over each sponge and carefully flip them upside down to release from the baking tins. Peel off the baking paper carefully, and then sift more icing sugar over the bottom of the sponges. While the sponges are still warm, roll them up in the baking paper starting at the short ends. Set the sponges seam side down and leave to cool completely.
  • For the buttercream: Place the butter in a large bowl and using an electric hand-whisk or a stand-mixer, whisk on a high speed until the butter is creamy and light. Then add the icing sugar, and whisk on a slow speed until combined. Then increase the speed to high and whisk for a few minutes until creamy and light. Add in the peppermint extract and milk and whisk again until combined. Finally, add a small blob of food colouring and whisk until combined. Then set aside.
  • To assemble: Unroll the sponges and cut each in half to create four long and thin strips. Then using a palette knife, spread some of the buttercream on each strip. Then roll one strip, from the short end, to make a swiss roll and place upright onto your serving platter. Then wrap the remaining three strips around the centre roll, starting each strip at the end of the last. You will end up with a large spiral of cake and filling. Then cover the entire cake in a thin layer of buttercream and place in the fridge to chill for 15minutes. Then cover the cake with the remaining buttercream. Finally, decorate with mint leaves and chocolate shavings if desired.

Notes

Cake is best served same day, but will keep in an air-tight container for 2-3 days. 
Keyword buttercream, chocolate, genoise, mint, vertical cake