For Streusel: Combine ½ cup uncooked oats, ¼ cup flour, ¼ cup firmly packed brown sugar, and 3 tablespoons melted tub margarine. Set aside.
Heat oven to 350 degrees.
- Place 3 tablespoons soft margarine (cut into pieces) in 8-inch square baking dish. Bake 3-5 minutes or until margarine is melted. Remove from oven. Combine 1/3 cup granulated sugar, 1 teaspoon cinnamon, and 3 medium apples cut into thin wedges. Add to baking dish, and return to oven. Bake 10-15 minutes or until apples have softened. Remove from oven.
- In large bowl, combine 1 cup flour, ½ cup uncooked oats, 1 teaspoon baking powder, and ¼ teaspoon salt. In small bowl mix together 1 cup skim milk and 1 egg; blend well. Pour milk mixture into dry ingredients all at once; stir just until ingredients are moistened. Do not overmix.
- Spoon batter over the apple mixture, spreading batter to the sides of the dish. Sprinkle streusel mixture evenly over the top. Bake 25-30 minutes.