l ½ tsp. baking powder
cup brown sugar
Cream butter, sugar, and egg. Add dry ingredients. Put half of crumbs on bottom of pan. Cook filling of blueberries, brown sugar and water. Dissolve cornstarch in a small amount of cold water and stir in until thick. Put filling over bottom crust and sprinkle with remaining crumbs. Bake until golden brown about 30 minutes at 350°F.