Chocolate sponge Mk II

Same ingredients as before but with 40g cocoa sifted into the flour and the whites whisked and folded in at the end.

So, separate the eggs, whisk the whites and put in a bowl
Put the butter in the Kenwood Cooking Chef, set to 40°C, beat. Beat the eggs in a cup and add an espresso. Add to the mix, turn off the heat.
Sift the flour, baking powder, sugar and cocoa into a big jug, stir and add to the mix. Finally fold in the egg whites.
1/3 fill the cake tin, grate on chocolate, another 1/3, more grated chocolate and then the rest of the mix. Wrap newspaper around the tin and bake for 40 minutes, remove the paper and bake till done

 and it ends up like this

The newspaper trick is to slow down the heat into the sides so the middle cooks properly. The kitchen stinks of printers ink but it doesn't go into the cake, next time I'll use clean stuff or a wet towel

Final view