Heat oven to 375°. Grease and flour a square pan, 9x9x2 inches. Mix sugar, shortening and egg thoroughly. Stir in milk. Blend dry ingredients; stir in. Blend in 2 cups of well-drained blueberries. Spread the batter in the pan and sprinkle the top with a mixture of ½ cup sugar, 1/3 cup flour, ½ teaspoon cinnamon and ¼ cup soft butter. Bake 45 to 50 minutes.