How to Make It
Preheat oven to 350°F. Spread chopped apples evenly in the bottom of a lightly greased (with cooking spray) 11- x 7-inch baking dish.
Stir together oats, toasted pecans, sugar, baking powder, cinnamon, and salt in a large bowl. Whisk together milk, eggs, and vanilla. Gently stir milk mixture into oat mixture until well incorporated. Gently stir in melted butter until just incorporated. Fold in raisins. Pour mixture over apples in prepared baking dish. Top evenly with chopped pecans.
Bake in preheated oven until browned and set, 40 to 45 minutes. Let stand 5 minutes.