1. Preheat oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.

2. In a food processor, pulse pistachios until finely ground (do not over-process into paste).

3. In a medium bowl, whisk together ground pistachios, flour, baking powder, and salt.

4. In a large bowl, cream butter and sugar together until light and fluffy.

5. Add eggs one at a time, beating well after each, then mix in vanilla extract.

6. Alternate adding dry ingredients with milk and sour cream, beginning and ending with the dry mix.

7. Divide batter evenly between prepared pans and smooth tops.

8. Bake for 25–30 minutes, or until a toothpick inserted into the center comes out clean.

9. Cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

10. For the frosting, beat mascarpone, heavy cream, powdered sugar, and almond extract until smooth and fluffy.

11. Frost cooled cakes, stack, and garnish with chopped pistachios for an elegant finish.