Heat oven to 400. Grease 9 x 9 square pan. Mix baking mix, milk, sugar and egg; beat vigorously 30 seconds. Spread half of the batter in pan. Arrange apple slices on batter; sprinkle with half of the topping. Spread remaining batter over apple slices; sprinkle with remaining topping. Sprinkle with nuts. Bake about 25 minutes, cool. Drizzle with glaze. Topping: Combine dry ingredients, then cut in margarine.