Heat the oven to 356°F (180 °C). You're going to need 2 cake forms that are 9″ (23 cm) in diameter each. In a bowl, sift the flour, powdered sugar, 3 tbsp cocoa, the baking powder, baking soda and 1/2 tsp salt.
Dissolve 1 tbsp coffee in a cup.
In a bowl, combine the milk, 2 large eggs, 1/2 cup oil and the vanilla. Beat briefly at a lower mixer speed. Carefully add the dry ingredients in small parts, and once half of them are in, start adding the hot coffee. Alternate between dry ingredients, hot coffee and finish off with the flour.
Divide this mixture into 2 parts, bake them about 30 min. and then cool them.
Put 8 oz (230 g) dark chocolate, 2 tbsp cocoa, 1 tsp instant coffee, 1 tbsp rum and 5 tbsp water in a suitable casserole. Put them on very low heat and stir energetically. You need to get a smooth and shiny mixture without lumps. Then leave it aside.
Separate the yolks from the whites in 2 of the eggs. Add 1/2 tbsp sugar to each of them separately. Whip the yolks until you get a nearly white cream. Whip the whites the same way with 1 pinch salt until you get a hard snow. Then beat 4/5 cup (200 ml) confectionery cream and begin combining them.
Add the chocolate mixture to the yolks and stir well. Then add the whites a little bit at time, while stirring to homogeneity. Next, add the whipped confectionery cream. What you get is a mousse with an amazing taste.
Put the finely crumbled 2 types of chocolate (milk chocolate - 2 oz (50 g) and dark chocolate - 2 oz (50 g)) in a suitable container, along with 1 tbsp coffee (powdered). Heat them briefly and stir very quickly, add 2/5 cup (100 ml) un-whipped cream and continue stirring. Remove from the heat and continue stirring, while also adding 2 tbsp melted butter. Pour the glaze over the cake right away because it thickens quickly.
Put the cream between the layers, at the very top and sides of the cake. After you've put it together, put it briefly in the fridge to harden. Then add on the warm glaze.
For decoration I used an additional 2/3 cup (150 ml) confectionery cream and wafer rolls.