Preheat the oven to 375 °F. Lightly spray a 9x13-inch baking dish with nonstick spray.
In a large bowl, whisk together the applesauce, peanut butter powder and maple syrup.
Use a whisk to beat in the egg and egg white.
Whisk in the peanut butter, vanilla extract, baking powder, cinnamon and salt
Stir in the milk
Stir in the oats
Stir in the trail mix
Pour the mixture into the prepared baking dish. Bake at 375 °F for about 45 minutes. Oatmeal is done when the edges turn golden-brown and a toothpick/knife inserted into the center of the oatmeal comes out clean.