Preheat the oven at 175 degrees Celsius.
Melt the butter and let it cool down.
With an electrical mixer mix the eggs and the sugar.
While still whipping add the cardamom powder, vanilla sugar and salt.
Grate the almond paste and pour it down in the batter. Stir it in gently.
Add the almond flour, rice flour and stir.
Add the melted butter and mix it all well.
Butter a baking form or a pie form.
Place in the middle of the oven for 25 minutes.
Take out the mud cake and let it cool down in room temperature.
Before serving the cake whip the cream, and sprinkle the cake with some icing sugar.