hazelnuts, coarsley chopped
Grease a springform pan with detachable bottom that has a diameter of about 9 1/2 inches.
Melt cooking chocolate and butter in a thick-bottomed pot over low heat.
Beat eggs and sugar until light and airy; carefully stir the somewhat cooled chocolate mixture into egg mixture.
Blend flour, nuts, and baking powder together, and fold carefully into batter - It's important to fold it in gently.
Pour batter into pan and bake in the oven for about 15 minutes - The cake should not become firm.
(The "unbaked" batter tastes like a delicious filling).
You may garnish cooled cake with a bit of grated chocolate and a ring of whipped topping.