Meanwhile, in 8-inch nonstick skillet, heat reserved 1/2 cup oat mixture over medium-low heat 2 to 3 minutes, stirring occasionally, until lightly toasted. Spread apple pie filling over partially cooled cheesecake. Sprinkle toasted oat mixture on top. Cool 1 1/2 hours. Refrigerate 4 hours or overnight. Run metal spatula along side of cheesecake to loosen; remove side of pan. Store in refrigerator.