Dice dates for the cake. Bring Amaretto and 100 ml water to the boil in a small pot and simmer for 2-3 minutes until the liquid has almost evaporated. Remove the pot from the stove and let it cool down.
Break 200 g chocolate into pieces. Melt with 200 g butter in a bain-marie and let it cool down lukewarm. Coarsely chop the nuts. Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer).
Grease a square springform pan (approx. 24 x 24 cm; alternatively a round one of 26 cm Ø). Cream eggs, 200 g sugar and 1 teaspoon vanilla flavouring with the whisks of the mixer. Mix flour, cocoa, baking powder and baking soda.
Stir the chocolate mixture into the egg mixture. Fold in dates and half the nuts. Smooth the dough in the tin. Bake in a hot oven for about 30 minutes.
For the chocolate sauce, chop 75 g chocolate. Heat the cream, 150 g sugar, 50 g butter and 1 teaspoon vanilla flavouring in a saucepan. As soon as the butter has melted, remove the pot from the heat and melt the chopped chocolate in it while stirring.
Remove the cake from the oven and prick it several times with a wooden skewer. Approx. 2⁄3 of the chocolate sauce onto the cake. Sprinkle with remaining nuts. Bake in the hot oven for another 5 minutes. Let the chocolate cake cool down and cut into pieces.
Serve the rest of the sauce with the cake.