Preheat oven to 350°F (175°C). Grease and flour two 8-inch round cake pans.

In a food processor, pulse the pistachios until they reach a fine, flour-like consistency. In a medium bowl, whisk together the all-purpose flour, ground pistachios, baking powder, baking soda, and salt.

In a large bowl with an electric mixer, cream the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the oil and vanilla.

Alternately add the dry ingredients and buttermilk to the wet ingredients, beginning and ending with the dry. Mix on low until just combined. Do not overmix.

Pour batter evenly into the prepared pans. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Let cool in pans for 10 minutes, then invert onto a wire rack to cool completely.

For the filling, combine raspberries, sugar, and lemon juice in a small saucepan over medium heat. In a small bowl, make a slurry with the cornstarch and 1 tbsp of water. Add to the saucepan and cook, stirring, until thickened. Cool completely.

For the buttercream, beat the butter and cream cheese until creamy. Gradually add the powdered sugar, then beat on high for 3-5 minutes. Mix in the vanilla and heavy cream.

To assemble, place one cake layer on a plate. Pipe a dam of frosting around the edge. Fill with the cooled raspberry filling. Top with the second cake layer. Cover the entire cake with a thin crumb coat and chill for 30 minutes. Frost with the remaining buttercream and garnish with fresh raspberries and chopped pistachios.