Gather your ingredients.
Lightly grease a 9-inch springform pan. Line the bottom and sides with greaseproof paper and put to one side. Preheat the oven to 325 F.
In a large non-stick saucepan, melt the remaining butter on low heat. Add the chopped chocolate to the pan and stir until melted. Remove from the heat instantly and leave to cool for 10 minutes.
Beat the egg yolks, both sugars, and the amaretto in a stand mixer until frothed up and doubled in volume. If you do not have a stand mixer, an electric or hand whisk will work too.
Using a fine sieve, sift the cocoa powder over the beaten egg and sugar mixture, then mix on low speed. You do not want to beat the air out of the eggs or the cake will not rise when cooked.
Put the egg whites in a scrupulously clean bowl and using clean beaters, whisk until the whites start to stiffen and are slightly glossy.
The chocolate should now be cooled enough fold gently into the egg mixture using a metal tablespoon. Gently stir 1/3 of the beaten egg whites into the mixture, then gently fold the remaining 2/3, making sure it is evenly colored with no streaks of chocolate.
Carefully spoon the mixture into the prepared pan and tap on the work surface a couple of times to release any air bubbles.
Bake in the center of the preheated oven for 50 minutes until set, but not solid. The center should spring lightly to the touch. The surface of the cake may crack a little but don't worry, it's a feature of this style of cake.
Remove from the oven and place the pan on a cooling rack and leave to cool completely.
Drench the cake with a heavy dusting of cocoa powder, garnish with fresh raspberries, raspberry sauce, and cream if desired. Elaine Lemm