Ingredients – serves 8

For the chocolate sponge base:

• 2 eggs
• 40 g flour
• 20 g cocoa powder
• 60 g sugar

For the vanilla sponge with cocoa paste decor:

• 2 eggs
• 60 g flour
• 60 g sugar
• 1/2 egg white
• 10 g cocoa powder
• 10 g flour
• 15 g sugar
• 15 g butter

For the chocolate truffle filling:

• 250 g dark chocolate
• 2 tablespoons honey
• 500 ml double cream

For the dark chocolate ganache:

• 35 ml double cream
• 50 g dark chocolate

For the crunchy cocoa lace topper:

• 1/2 egg white
• 10 g cocoa powder
• 10 g flour
• 15 g sugar
• 15 g butter

Method

Make the chocolate sponge base:

• Heat the oven to 180C/160C fan/gas 4.
• Break the eggs into a bowl, add the sugar and whisk until pale, fluffy and thickened.
• Sift the flour and cocoa over the mixture and fold in carefully until well combined.
• Put baking parchment on a baking tray, pour the mixture onto the parchment and smooth with a spatula until evenly spread out.
• Bake the sponge for 10 minutes. Take out of the oven and leave to cool for a few minutes, then peel off the parchment.
• Put the base of an 18 cm springform tin on the sponge and cut around the edge with a sharp knife.
• Put the cut out circle of sponge in the springform tin.

Make the vanilla sponge with cocoa paste decor:

• Heat the oven to 180C/160C fan/gas 4.
• Mix 1/2 egg white, 10 g cocoa powder, 10 g flour, 15 g sugar and 15 g butter together and pour into a piping bag.
• Line a baking sheet with baking parchment, pipe a swirly pattern on the parchment and put in the freezer for 10 minutes.
• Break the 2 eggs into a bowl, add 60g sugar and whisk until pale, fluffy and thickened.
• Sift 60g flour over the mixture and fold in carefully until well combined.
• Take the baking sheet from the freezer, pour the sponge mixture over the swirly pattern and smooth with a spatula until evenly spread out.
• Bake the sponge for 10 minutes. Take out of the oven and leave to cool for a few minutes, then peel off the parchment.
• Cut the sponge into rectangular strips and line the sides of the springform tin with the sponge strips.

Make the chocolate truffle filling:

• Break the chocolate in small pieces into a large pan.
• Spoon in the honey and pour in 150 ml of the cream.
• Put on the lowest possible heat and stir until the chocolate has melted and everything is combined. Take of the heat and set aside.
• Put the rest of the cream into large bowl and whisk until the cream looks like a thick milkshake.
• Pour the melted chocolate into the bowl containing the whisked cream and fold together until they are evenly and smoothly mixed.
• Pour the mixture into the prepared springform tin, put in the fridge and leave to firm up for 2 hours.

Make the crunchy cocoa lace topper:

• Heat the oven to 180C/160C fan/gas 4.
• Mix all ingredients together and pour into a piping bag.
• Put baking parment on a baking tray and pipe a round swirly pattern on the parchment.
• Bake for 10 minutes, take out of the oven and leave to cool.

Make the dark chocolate ganache:

• Heat the cream in a small pan until just steaming, then take off the heat.
• Break the chocolate in small pieces.
• Add the chocolate to the warm cream and leave to melt for 5 minutes.
• Stir to make a glossy ganache, then set aside to firm up a little.

Assemble the gâteau:

• Remove the cake from the tin.
• Pour the dark chocolate ganache on top of the cake and leave to set for 15 minutes.
• Put the crunchy cocoa lace topper on top and serve.