Preheat oven to 350°F
Lightly butter a 1-quart baking dish or a similar-sized dish.
Whisk cottage cheese, eggs, vanilla, and maple syrup until well combined.
Stir in the steel-cut oats, cinnamon, baking powder, and salt.
Fold in chopped apple.
Pour mixture into the prepared baking dish and bake for 40-45 minutes or until golden brown and set in the center.
Let cool for 5 minutes and serve.