Combine flour, oats, sugar, baking powder and salt in a medium bowl. Combine 1 ½ cups apple sauce, milk, egg and oil; add all at once to flour mixture. Stir only until moistened. Spray muffin tin with cooking spray; fill muffin cups ⅔ full with batter. Make a slight depression in top of each muffin; fill with 1 tbsp. apple sauce. Bake at 400°F about 25 minutes or until golden on top.