Preheat the oven at 175 degrees Celsius.
With a baking paper cover a baking form approximately 23cm in diameter, both the bottom and edges.
Melt the butter in a sauce pan. Pour it over in a bowl.
Add the almond paste and mix with an electrical mixer.
Add the vanilla sugar, flour, salt, sugar and cardamon powder. Mix it all well.
Pour the batter in the baking form. Place in the middle of the oven for 25 minutes.
Take out the mud cake and let it cool down for minimum 3 hours, but best is to let it rest over the night.
Whip the cream and the icing sugar to a hard foam.
Decorate the cake as you like.