Heat oven to 375°F. Grease 13x9-inch pan with shortening or cooking spray. In large bowl, mix flour and 1/2 cup sugar. Cut in 1/2 cup butter, using pastry blender (or pulling 2 table knives through ingredients in opposite directions), until mixture resembles coarse crumbs. Add milk and egg; stir just until blended. Spread batter evenly in pan.