I would love to provide a picture of the cake as a whole with its silky, chocolate custard covering but once I removed it from the fridge to serve, it didn’t last two seconds before everyone crowded round for a slice! I made this for my little brother’s birthday. He is a massive chocolate fan and this cake certainly delivers in that respect.
For the chocolate sponges:
- 150ml vegetable oil, plus extra for greasing
- 200g plain flour
- 70g cocoa powder
- 2 tsp baking powder
- 1 tsp bicarbonate of soda
- 200g light brown soft sugar
- 200ml buttermilk
- 100ml strong coffee
- 2 tsp vanilla extract
- 2 large eggs
For the chocolate custard:
- 250g golden caster sugar
- 500ml full-fat milk
- 140g chocolate, 85% cocoa solids, broken into cubes
- 50g cornflour
- 2 tsp espresso powder
- 2 tsp vanilla extract
- Make the custard first as it needs to chill. Put all the ingredients, except the vanilla, in a large pan and bring gently to the boil, whisking all the time, until the chocolate has melted and you have a silky, thick custard. It will take 5-7 minutes from cold. Stir in the vanilla and a generous pinch of salt then scrape the custard into a wide, shallow bowl. Cover the surface with cling film, cool then chill for at least 3 hrs or until cold and set.
- Heat oven to 180C/160C fan. Grease and line two 20cm cake tins with baking parchment – if your cake tins are quite shallow, line the sides to a depth of at least 5cm. Put flour, cocoa powder, baking powder, bicarbonate of soda, light brown soft sugar and 1 tsp salt in a bowl and mix well. If there are any lumps in the sugar, squeeze these through your fingers to break them up.
- Measure the buttermilk, coffee, oil and vanilla in a jug. Add the eggs and whisk until smooth. Pour the wet ingredients into the dry and whisk until well combined. Pour the cake mixture evenly into the two tins, and bake for 25-30 mins until risen and a skewer inserted into the centre comes out clean. Cool in the tins for 10 mins, then turn out onto a wire rack, peel off the baking parchment and leave to cool.
- To assemble, cover one of the cake layers with a generous helping of the custard. Add the second layer to the top of this and spoon the remaining custard on top of the cake then spread it around the top and down the sides until smooth. Chill for 15 minutes to firm up the custard again.
Chill for 2 hours, or longer if possible, before serving, and eat it cold. This cake can be made up to 2 days ahead. The cake gets fudgier and more enticing the longer you leave it. The coffee in the recipe cannot be tasted but really brings out the intense cocoa flavours in the custard and the sponge and the addition of a small pinch of salt in the custard really intensifies the chocolate even further.