grease an 8×8 baking dish.
in a large bowl, stir together the oats, sugar, baking powder, salt and cinnamon. in another bowl, whisk together the milk, egg, applesauce and vanilla. pour the liquid ingredients into the oats and stir to combine.
add in the peanut butter and mix until well combined. fold in apples.
bake for 35 minutes, or until set and golden. let cool for a few minutes before serving. 