cook or buy a round cake of your choice (carrots, chocolate, etc.). Cover the surface of a table with a tablecloth or paper and place the cake in the middle. Cover the top of the cake with a good layer of ground hazelnuts (about 0.5 cm). Sprinkle the cake generously with icing sugar using a colander to avoid lumps. Sprinkle again with a little chocolate powder to darken the surface. Stand on a chair and drop small and heavy objects on the cake. Vary the height of the drops to form craters of different sizes.
Take a large black baking tray (to simulate space) and carefully transfer your cake in the middle.