Preheat your oven to 340ºF (170ºC). Prepare three 8-inch round baking pans by lining the bottom with parchment paper and greasing the sides.

In a food processor, blend the unsalted pistachios until they reach a flour-like consistency. Sift together the pistachio flour with all-purpose flour, baking powder, baking soda, and salt.

Cream the butter and granulated sugar in a large bowl until light and fluffy.

Add eggs two at a time, mixing thoroughly after each addition. Gradually incorporate the dry ingredients, sour cream, oil, and vanilla until just combined.

Divide the batter among the three prepared pans. Bake for 20-23 minutes or until a tester comes out clean.

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

In a saucepan, combine frozen raspberries, sugar, vanilla, and lemon juice. Cook until bubbly, then lower heat and simmer for 8 minutes.

Mix cornstarch with water and stir into the raspberry mixture to thicken, refrigerate until cool.

Beat room temperature butter until fluffy. Gradually add powdered sugar and raspberry powder, mixing until well combined.

Add vanilla extract and milk, mixing until smooth and adjusting milk for desired consistency.

Place the first layer on a serving platter. Spread buttercream followed by raspberry jam. Repeat with the second layer.

Place the final layer on top and apply a crumb coat of buttercream around the entire cake.

Refrigerate the cake for about 30 minutes to set the crumb coat.

Apply a final layer of buttercream and decorate with fresh raspberries and chopped pistachios.