Heat your milk and crumble yeast into it. Add salt, sugar, egg, and cardamom and whisk well. Add flour little by little. Grate your butter and mix everything well together, knead your dough for 10 minutes until it is no longer sticky. Let your dough rise for 1.5 hours in a warm place. Then form your buns on a baking sheet with parchment paper and let them rise again for 30 minutes. Brush them with egg or milk and bake them in the oven at 200 degrees Celsius (392 degrees Fahrenheit) for about 15-20 minutes until they are golden. Meanwhile, make your almond cream. First, blend your cooled roasted almonds into a fine flour. Add the remaining ingredients and blend until you get a creamy almond mixture. Put it in a piping bag. Cut a triangle in your buns and take the top off. Hollow out your buns and remove some of the filling so there is space for the almond cream. Fill the almond cream in the bun. Whip your cream, powdered sugar, and vanilla into a foam and put it in a piping bag with a nozzle. Pipe the vanilla cream on top and place the cut-out triangle on top. Sprinkle with a little powdered sugar and serve.