- Butter for greasing
- 300g/2 cups of broken plain/semi-sweet chocolate (or 150g/1 cup of dark, 150g/ 1 cup of milk chocolate), plus extra to decorate (optional)* 225g/1 cup of caster/superfine sugar
- 180ml/3⁄4 a cup of boiling water
- 225g/1 cup of salted butter, cut into cubes
- 6 eggs, separated
- 1 teaspoon of instant coffee powder
- 1 tablespoon of vanilla extract
To top the cake
- 125g/1 cup of raspberries, whole
- 125g/1 cup of strawberries, quartered
- 200ml/7fl oz tub of crème fraîche
- Grease and line the base of a solid-bottomed 20-cm/8-inch square or 23-cm/9-inch round cake tin/pan (though I prefer to use a springform cake tin as the texture of the cake is quite moist and sticky). Preheat the oven to 180oC/160oC fan/Gas 4.
- In a large food processor (or done in two batches), pulse the chocolate and sugar until fine. Add the boiling water, butter, egg yolks, coffee powder and vanilla extract. In a glass bowl, whisk the egg whites until stiff and then add them to the mixture in the food processor and blend for 10 seconds or so. Pour the mixture into the prepared cake tin/pan and put in the hot oven for 45–55 minutes. The top will be cracked like a desert fault line.
- After you take the cake out of the oven it will collapse in on itself quite a bit. This is ok; it’s not meant to be a proud cool cake, it’s meant to be slightly rough around the edges and home-made, and the crème fraîche and berries will hide any dips and cracks!
- Let the cake cool, then put it in the fridge for a few hours. When you are ready to serve, remove from the tin/pan and smother it in raspberries, strawberries and crème fraîche. You can also grate some more chocolate on top.