The best chocolate cake

Dough:
wheat flour 2 cups
sugar 1.5 cups
margarine 250 grams
milk 0.5 glass
egg 4 pieces
cocoa 4 tbsp
baking powder 1 tbsp
coffee flavoring a few drops
Topping:
cocoa 2 tbsp
sugar 5 tablespoons
30% cream 3 tablespoons
butter2 spoons