Variations:
Add 1/2 cup of toasted sliced almonds to dry ingredients and 1/4 teaspoon of almond extract to the sour cream mixture.
Add one cup of white chocolate chips and 1 tablespoon of orange zest to the sour cream mixture.
Use blueberries or other berries in place of raspberries. Add 2 teaspoons of grated lemon or orange rind.