This mixture also works to make a Swiss roll; to do so, bake the mixture 1cm thick in a shallow tray on greaseproof paper. It will take less time to bake, so check regularly. Once baked and cooled, spread with the filling and whipped cream, and carefully roll up, unpeeling from the paper as you go.

Serves 10

SPONGE
8 eggs, separated
200g caster sugar
65g cocoa powder
FILLING
225g good quality dark chocolate, chopped up
2 large eggs, separated
200g fruit jam (plum, cherry, blackcurrant)
OPTIONAL
400g double cream, whipped

Begin by making the sponge. Line and grease two circular cake tins and preheat oven to 180C/gas mark 4.

Whisk the egg yolks in a large bowl until they start to thicken. Add the sugar and continue to whisk until the mixture becomes thick and pale. Sift the cocoa powder into the yolk mixture until combined

In another bowl, whisk the egg whites until they form soft peaks. Gently fold the egg whites into the cocoa mix, trying to keep as much as possible in the batter. When mixed, transfer into cake tins and smooth the tops. Bake for 20-30 minutes, until well risen and the top springs back to touch. Remove from oven and allow to cool in the tins.

While the cake is baking, make the filling. Melt the chocolate in a heatproof bowl over a pan of boiling water, stirring frequently (or you can microwave on 30 second bursts, stirring between each). When chocolate is nearly melted, remove from the heat and beat with a spoon until the lumps are fully blended. Allow to cool slightly.

In a small bowl, lightly beat the egg yolks to loosen them and add the melted chocolate. Whisk until completely combined and smooth.

In a very clean bowl, whisk the egg whites until stiff. Gently fold the egg whites into the chocolate mixture, until completely incorporated and smooth. Chill the filling for an hour.

When the cakes and the filling are both chilled you can assemble the cake. Spread the jam onto of one sponges and then spread a layer of the chocolate mousse onto of this. Sandwich the cakes together and repeat a layer of jam and mousse on the top of the cake. Decorate with swirls of whipped cream or on the side for extra decadence.

This recipe is shared as part of the Good Food Club. We are very grateful for funding from The National Lottery Community Fund, distributed by the Landworkers’ Alliance, which has allowed us to offer a pilot of the Good Food Club this year. Thanks to National Lottery players for making this possible.