01 - Preheat oven to 350°F. Grease and line a 9-inch round cake pan with parchment paper.
02 - Whisk together flour, ground pistachios, baking powder, and salt in a bowl. Set aside.
03 - Beat butter and sugar in a large mixing bowl until pale and fluffy, approximately 3 minutes.
04 - Add eggs one at a time, beating well after each addition. Mix in vanilla extract.
05 - Add half the dry ingredients to the wet mixture and mix gently. Pour in milk, then add remaining dry ingredients, mixing until just combined.
06 - Gently fold raspberries into the batter, taking care not to crush them.
07 - Transfer batter to prepared cake pan and smooth the top evenly.
08 - Bake for 38-42 minutes, or until a toothpick inserted into the center comes out clean.
09 - Let cake cool in the pan for 15 minutes before transferring.
10 - Transfer to a wire rack to cool completely. Dust with powdered sugar and sprinkle chopped pistachios if desired.