For the Filling: Gently rinse mulberries in cold water. Combine flour and sugar in medium bowl. Toss gently with berries. For Assembly: Combine flour, sugar and baking powder in mixing bowl. Cut in butter with pastry blender or 2 knives until mixture resembles coarse crumbs. Add egg; mix slightly, stirring just to moisten. Grease 8-inch square baking dish. Fill with berry mixture. Crumble topping over berries. Bake at 350 degrees until slightly golden brown, 30 to 35 minutes. Serve with vanilla ice cream or chilled whipped cream. This recipe yields 6 to 8 servings. Each of 8 servings: 118 calories; 143 mg sodium; 47 mg cholesterol; 8 grams fat; 10 grams carbohydrates; 2 grams protein; 0.51 gram fiber.