How to make pressed chocolate cake

To decorate, dust with icing sugar and cocoa powder, then add crystallised violets and sugar stars. Photograph: Claire Thomson
With three children, the birthday cakes come thick and fast. So far, we've had ballerinas protruding from the tops of panettone, a farmyard with pigs and chocolate fences, a liquorice ladybird, a Smartie-pebbledashed house and a banana and toffee bear. It's my daughter's seventh birthday soon. Like most kids, she loves chocolate (less commonly, she hates icing), and I know she's hoping for something beautiful with flowers. My take on this River Café recipe for a pressed chocolate cake is perfect.
I've reduced the sugar and rather than pressing the cake with a same-sized plate, I like to use a smaller plate so the outskirts of the cake remain high, giving it a lovely raised lip to dust with icing sugar. To decorate, dust the centre with cocoa powder, then add crystallised violets and white sugar stars. Simple, stark and very pretty indeed.
Pressed chocolate cake
(Serves 10)
400g good-quality dark chocolate, broken into pieces
300g unsalted butter
10 eggs, separated
175g caster sugar
4 tbsp cocoa powder, plus extra to decorate
Icing sugar
Crystallised violets and white sugar stars
Preheat the oven to 180C/350F/gas mark 4.
Butter and line with greaseproof paper a 30 x 7.5cm (12 x 3in) high-sided spring-loaded cake tin, pressing the paper right into the tin.
Melt the chocolate with the butter in a bowl over a pan of simmering water – don't let the water touch the bottom of the bowl.
Remove the bowl when the chocolate and butter have melted, and allow to cool a little.
Whisk the egg yolks with the sugar and cocoa powder, then add to the chocolate.
In a separate clean bowl, beat the egg whites until they form soft peaks. Fold into the chocolate mixture, one third at a time.
Pour the mixture into the prepared cake tin and bake for about 25 minutes. The cake will souffle, set slightly and cracks will appear on the surface at the edges. The cake should retain a wobble at the centre. Take it out and place two side plates on top of each other in the centre of the cake to press. Leave to cool for half an hour.
Release the cake from the spring-loaded tin and, with the plates still on, dust the edges of the cake with icing sugar.
Remove the plates and decorate with cocoa powder, crystallised violets and sugar stars.