Start by processing shelled pistachios in a food processor until they are finely ground. In a bowl, whisk together the ground pistachios, all-purpose flour, baking powder, and salt. Set aside.

Cream together softened unsalted butter and granulated sugar using an electric mixer until light and fluffy, about 3-4 minutes. Gradually add in eggs one at a time, mixing well after each addition. Blend in the whole milk, vegetable oil, vanilla extract, and almond extract.

Gently fold the prepared dry mixture into the wet ingredients using a spatula, being careful not to overmix. The batter will have a lovely pale green hue from the pistachios.

Preheat your oven to 350°F (175°C). Divide the batter among three greased 8-inch round cake pans. Bake for 22-25 minutes, checking for doneness with a toothpick. Allow them to cool on wire racks.

Whip the heavy cream until soft peaks form. Fold in the mascarpone cheese and sifted powdered sugar with a splash of vanilla extract until smooth. Chill the mascarpone cream.

Once the cake layers are completely cool, place one on a serving plate and spread a layer of mascarpone cream. Repeat with the second layer, then fully frost the top and sides with the remaining cream.

Garnish the top with chopped pistachios and optional white chocolate shavings or edible gold leaf.

Cover loosely with plastic wrap or a cake dome and refrigerate for at least 2 hours before serving.