1 tbsp. butter
1 1/2 c. flour
1/2 c. sugar
1/2 c. butter, room temperature
1 1/2 tsp. baking powder
1 egg
1 1/2 tsp. vanilla
4 c. blueberries

CUSTARD:

2 c. sour cream
2 egg yolks
1/2 c. sugar
1 tsp. vanilla

Position rack in center of oven and preheat oven to 350 degrees. Generously butter 9-10 inch spring-form pan. In large bowl, combine flour, sugar, 1/2 cup butter, baking powder, egg, and vanilla; mix thoroughly. Turn into prepared pan and sprinkle evenly with blueberries. Bake 1 hour.