Combine apple pie filling and lemon peel, then spread in 9-inch pie plate.
Combine flour with brown sugar in medium bowl. With fork, stir in Hellmann's® or Best Foods® Real Mayonnaise until mixture is size of small peas. Stir in oats and walnuts. Evenly sprinkle over apples.
Bake 30 minutes or until heated through and topping is golden. Serve warm or at room temperature. Dust with confectioners' sugar if desired.