For biscuit topping, in a medium mixing bowl stir together the flour, the 2 tablespoons sugar, and baking powder. Cut in margarine or butter until mixture resembles coarse crumbs. Set aside.
For filling, in a medium saucepan combine the 1/3 cup sugar and cornstarch. Add thawed raspberries, water, and lemon juice. Cook and stir until thickened and bubbly. Stir in thawed cherries; cook and stir until bubbly again. Reduce heat and keep filling hot.
In a small bowl use a fork to beat together egg and milk. Add egg mixture all at once to the biscuit topping. Using a fork, stir just until moistened.
Transfer the hot filling to an ungreased 2-quart square baking dish. Immediately drop topping mixture from a teaspoon into small mounds atop filling. Combine the 1 tablespoon sugar and the cinnamon; sprinkle over topping. Sprinkle with pecans. Bake, uncovered, in a 400 degree F oven 20 to 25 minutes or until toothpick inserted in center of topping comes out clean. If desired, serve warm with ice cream. Serves 6.