Preheat your oven to 350°F (175°C).

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.

In a large mixing bowl, cream the softened butter and granulated sugar until light and fluffy.

Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract followed by buttermilk.

Gradually add the dry ingredient mixture to the wet mixture until just combined. Fold in the crushed pistachios.

Pour your batter into two greased 9-inch round cake pans.

Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.

Let the cakes cool in the pans for about 10 minutes, then transfer them to wire racks to cool completely.

In a mixing bowl, beat the heavy whipping cream until soft peaks form.

Gradually add powdered sugar and vanilla extract, then fold in the pistachio pudding mix.

Once the cakes are completely cooled, spread a layer of frosting on top of one cake layer.

Place the other layer on top and then frost the sides and top of the entire cake.

Decorate with leftover crushed pistachios if desired.

Cut yourself a slice, plate it, and serve.