Beat the sugar and butter and add the eggs one at a time, constantly beating. Melt the chocolate in a microwave briefly and add it to the mixture. Begin to add the flour and whip once more.
Pour the mixture into a greased baking dish and put to bake in a preheated 320°F (160 °C) oven for about 50 minutes. Cool the finished layer and cut it into 3 separate layers. Pour liqueur over each and stick them together with a cream mixture made from the mascarpone and whipped cream.