This pistachio cream cake surprised everyone, surpassing almost all my old recipes!

Ingredients:
200g all-purpose flour
1 1/2 tsp baking powder
1/2 tsp baking soda
1/4 tsp salt
100g unsalted butter, softened
50g sugar
2 eggs
1 tsp vanilla extract
120g sour cream (or quark)
120ml whole milk
100g shelled pistachios, finely chopped
80g white chocolate chips
For the frosting:
200g unsalted butter, softened
120g powdered sugar
120ml heavy cream
1 tsp vanilla extract
50g pistachios, finely chopped for garnish
Preparation: