Melt the chocolate in a bowl over a pan of simmering water (see
Separate all but one of the eggs, reserving the whites. Whisk the remaining whole egg, egg yolks and sugar in a bowl until the mixture is thick and pale and leaves a trail when the beaters are lifted.
Whisk in the melted chocolate slowly and then add the almonds. Clean the beaters and whisk the egg whites until softly peaking. Whisk one-quarter of the egg whites into the mix to loosen it, then fold in the rest.
Grease and line a round cake tin, 12 cm (5 inches) in diameter and 8 cm (3½ inches) deep, ensuring the nonstick baking paper comes about 7 cm (3 inches) above the tin. Pour the mixture into the tin and bake in a preheated oven, 160°C (325°F), Gas Mark 3, for 1–1¼ hours or until a skewer inserted into the centre of the cake comes out clean.
Make several holes in the cake while still hot and drizzle over the coffee liqueur. Cool in the tin for 30 minutes. To serve, place the cake on a stand, dust with cocoa powder, top with a pile of raspberries and wrap a wide ribbon around it.