Sift together flour, baking powder and salt. Cream together butter and sugar. Add egg and milk to butter mixture and beat until smooth. Add dry ingredients; fold in blueberries. Spread in a greased and floured 8 or 9 inch cake pan. Make topping by cutting the ingredients together until it forms course crumbs. Sprinkle over cake and bake for 40 minutes at 375. Recipe By : Oregon Sampler: Resorts and Recipes