Step 1: Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake pans or line with parchment paper.
Step 2: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
Step 3: In a large bowl, cream together the softened butter and granulated sugar with an electric mixer until light and fluffy (about 3-5 minutes).
Step 4: Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and almond extract (if using).
Step 5: Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix on low speed just until combined. Do not overmix.
Step 6: Gently fold in the finely ground pistachios and then carefully fold in the fresh raspberries, being careful not to crush them too much.
Step 7: Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
Step 8: Let the cakes cool in the pans for 10-15 minutes before inverting them onto a wire rack to cool completely.
Step 9: While the cakes cool, prepare the Raspberry Buttercream. In a large bowl, beat the softened butter until creamy. Gradually add the sifted powdered sugar, alternating with heavy cream or milk, beating until light and fluffy.
Step 10: Stir in the vanilla extract and salt. Add the strained raspberry puree and mix until fully incorporated. If desired, add a few drops of pink food coloring for a more vibrant color.
Step 11: Once the cakes are completely cool, level them if necessary. Place one cake layer on a serving platter. Spread about 1/3 of the buttercream evenly over the top. Place the second cake layer on top and cover the entire cake with the remaining buttercream.
Step 12: Garnish with fresh raspberries and chopped pistachios if desired. Slice and serve your beautiful raspberry pistachio cake recipe!