Simmer 1/2 cup butter, 1/2 cup sugar, and cream for about 4 minutes.

Stir in the grated marzipan.

Simmer until the marzipan has melted and the mixture is smooth.

Preheat the oven to 350F Grease a baking pan.

Whisk together the flour and baking powder. Set aside.

Cream together 1 cup butter, and 1+1/4 cups sugar

Beat in the vanilla extract.

Add eggs one at a time, making sure each is fully incorporated before adding the next.

Add the dry ingredients in thirds alternately with the milk.

Fold in the pistachios.

Spread the dough onto a greased sheet pan.

Use a rounded teaspoon to make depressions in the top of the batter.

Fill with pistachio cream.

Spread the butter marzipan mixture evenly over the top.

Bake for 30 minutes.

While still hot, sprinkle 1/4 cup sugar over the top.

Let the cake cool completely.

Cut and serve.