Preheat the oven to 350°F/177ºC. Prepare three 6-inch or two 8-inch cake pans by spraying the sides with cooking spray and fitting a parchment paper circle to the bottom of the pan.

Using a food processor, grind the pistachios into fine crumbs. You’ll still have about 1 and ½ cups of crumbs. Place 1 ¼ cups of the pistachio crumbs into a medium bowl and set the rest of the crumbs aside in a smaller bowl to use as garnish.

In the medium bowl with the pistachio crumbs, add the sifted cake flour, baking powder, baking soda, and salt. Whisk to combine and set aside.

In the bowl of your stand mixer, beat the butter on high for two minutes until light and creamy. Add the sugar and vegetable oil, continuing to mix on medium-high for another two minutes. Scrape down the bowl and paddle as needed. Turn the mixer to low speed and add the egg whites one at a time until well combined. Add the sour cream, vanilla extract, and almond extract, mixing for two minutes on high speed. Scrape down the bowl and paddle once more.

Turn the mixer to low and add the dry ingredients all at once. When beginning to combine, add the green food coloring (if using) and the whole milk in a slow, steady stream. Continue to mix on low until incorporated, about 1 minute.

Pour the batter evenly into the prepared cake pans and bake for 28-32 minutes. They’re done when they spring back to the touch and a toothpick inserted comes out clean. Let the cakes cool in the pan for five minutes before turning them onto a wire rack for a few hours of cooling.

With a food processor, grind the raspberries into a fine powder. Sift out the seeds and set the powder aside.

Whip the butter in a stand mixer on medium-high speed until creamy and light in color (5 minutes). Add vanilla, milk, and raspberry powder; mix on medium until fully combined.

Add the powdered sugar one cup at a time and mix on low speed, scraping down the bowl after each addition. Add a pinch of salt and continue mixing until fully combined and smooth, 1-2 minutes.

Whip the butter in a stand mixer on medium-high speed until creamy and almost white in color (7 minutes). Turn the mixer to low speed and add the powdered sugar a cup at a time, scraping down as needed. Add the vanilla extract and mix until fully combined.

Add the mascarpone and a pinch of salt, mixing on low until just incorporated, about 30 seconds. Stir a few times by hand with a rubber spatula to ensure smoothness.

Once the pistachio cakes are completely cooled, level them to your desired height. Add a swipe of raspberry buttercream onto a cardboard cake circle and place the first cake layer on top. Add a layer of raspberry buttercream as filling and repeat with the final cake layer.

Crumb coat the cake with raspberry buttercream, then refrigerate for at least 30 minutes to let the buttercream set firm.

Frost the cake with mascarpone frosting, using a cake comb to create a rounded texture on the sides. Keep the top edges raw. While the frosting is tacky, gently press the reserved pistachio crumbs around the bottom third of the cake. Garnish the top with fresh raspberries and more pistachio crumbs.