3 c. sifted cake flour
1 tsp. baking powder
1 tsp. baking soda
1 c. sugar
1/2 lb. butter at room temp.
2 eggs, beaten
1 c. sour cream
1 tsp. vanilla
1 (13-16 oz.) can blueberry pie filling

TOPPING:

1/4 c. cake flour
3 tbsp. butter, room temp.
1/4 c. sugar
Confectioners' sugar

Sift dry ingredients together in a large bowl. Cut in butter with blender, as for pie crust. Add eggs, sour cream and vanilla; beat well. Spread half the batter evenly into 13"x9" pan. Spoon pie filling on top. Spread evenly. Spread remaining batter over the filling, spreading as evenly as possible. Prepare topping by blending all ingredients, except confectioners' sugar, using a pastry blender, then sprinkle over batter. Bake in preheated 375 degree oven for 45 minutes or until done. Remove from oven; transfer to cake rack to cool completely. Sprinkle with confectioners' sugar.