For Tiramisu Magic, first cut the butter into cubes. Heat with the milk on the stove or in the microwave until the butter is melted. Then allow to cool. Separate the eggs. In a bowl, beat the egg yolks, sugar, mascarpone and coffee liqueur with a hand mixer until fluffy. Sift in the flour and gradually stir in the cooled milk-butter mixture.
Beat the egg whites with the hand mixer in a separate bowl on the highest speed until very stiff. Add a small amount of beaten egg whites to the batter and whisk thoroughly to combine. Gently but quickly fold in the remaining beaten egg whites. Pour the batter into the prepared baking pan.
Preheat the oven to 155 °C top and bottom heat (convection oven is not suitable). Let the dough rest in the baking pan for 5-10 minutes during the preheating phase. Then bake in the oven on the middle rack for 50-60 minutes. Baking time depends on how high the baking pan is.
The cake is done when the top layer is golden brown and the center still jiggles slightly when you move the baking dish. Remove the cake from the oven, be sure to let it rest overnight, and do not remove it from the pan and cut it until the next day.
Just before serving, mix the cocoa powder with the instant coffee and sprinkle over the Tiramsiu Magic cake.