1Grease bottom and sides of a 9 inch spring form pan with butter. Set aside.
Combine the first 3 ingredients and mix well in a medium bowl then add butter and mix with fingers until mixture is crumbly. Set aside.
In a large bowl, beat the one stick of butter and sugar until light and fluffy, about 2 minutes, decrease speed to low, add eggs one at a time. Add 1/2 of the sour cream, beat until combined.
4In a small bowl whisk together the flour, baking powder, soda and salt. Add 1/2 of this mixture to the sour cream mix and beat until combined. Repeat with remaining sour cream and vanilla. Then add rest of flour and mix well.
5Using a spatula gently fold in berries, stir sparingly to keep batter from turning blue. Spread batter in prepared pan. Sprinkle topping on top. Place pan on baking sheet, bake 55-60 minutes or until toothpick comes out clean. Remove to wire rack and cool. Release sides of pan. Serve warm or cool.