Cozy Apple Cinnamon Baked Oatmeal

Quick Recipe Version (TL;DR)

• Yield: 8 servings
• Prep Time: 15 minutes
• Cook Time: 40 minutes
• Total Time: 1 hour 5 minutes, including 10 minutes resting time

Quick Ingredients

• 2 cups old-fashioned rolled oats
• 1 1/2 teaspoons baking powder
• 2 teaspoons ground cinnamon, divided
• 1/4 teaspoon ground nutmeg
• 3/4 teaspoon fine salt
• 2 cups whole milk
• 2 large eggs
• 1/3 cup pure maple syrup
• 1/4 cup unsalted butter, melted and slightly cooled, plus more for the baking dish
• 2 teaspoons vanilla extract
• 2 large crisp apples, peeled if desired, cored and diced into 1/2-inch pieces, about 2 1/2 cups
• 1/2 cup chopped pecans or walnuts, optional
• 2 tablespoons packed light brown sugar
• 1 tablespoon old-fashioned rolled oats, for the topping

Do This

• 1. Heat oven to 350°F. Butter an 8-inch square baking dish.
• 2. Whisk oats, baking powder, 1 1/2 teaspoons cinnamon, nutmeg, and salt in a large bowl.
• 3. Whisk milk, eggs, maple syrup, melted butter, and vanilla in a separate bowl.
• 4. Stir apples and optional nuts into the oats, then mix in the wet ingredients.
• 5. Pour into the dish. Top with brown sugar, 1 tablespoon oats, and remaining 1/2 teaspoon cinnamon.
• 6. Bake 38 to 42 minutes, until set in the center and lightly crisp on top.
• 7. Rest 10 minutes before slicing. Serve warm with milk, yogurt, or maple syrup.

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Why You’ll Love This Recipe

• Warm and cozy: Tender apples, cinnamon, vanilla, and maple syrup make the whole kitchen smell like a fall morning.
• Easy to share: It bakes in one dish and slices neatly into hearty squares for breakfast, brunch, or meal prep.
• Soft inside, lightly crisp on top: The oatmeal bakes into a custardy, spoonable casserole with a delicate brown-sugar oat topping.
• Simple pantry ingredients: Rolled oats, apples, milk, eggs, and spices turn into something special with very little fuss.

Grocery List

• Produce: 2 large crisp apples, such as Honeycrisp, Fuji, Pink Lady, or Granny Smith
• Dairy: Whole milk, 2 large eggs, unsalted butter
• Pantry: Old-fashioned rolled oats, baking powder, ground cinnamon, ground nutmeg, fine salt, pure maple syrup, vanilla extract, packed light brown sugar, chopped pecans or walnuts if using

Full Ingredients

For the Baked Oatmeal

• Butter or nonstick baking spray, for greasing the baking dish
• 2 cups old-fashioned rolled oats
• 1 1/2 teaspoons baking powder
• 1 1/2 teaspoons ground cinnamon
• 1/4 teaspoon ground nutmeg
• 3/4 teaspoon fine salt
• 2 cups whole milk
• 2 large eggs
• 1/3 cup pure maple syrup
• 1/4 cup unsalted butter, melted and cooled for 5 minutes
• 2 teaspoons vanilla extract
• 2 large crisp apples, peeled if desired, cored and diced into 1/2-inch pieces, about 2 1/2 cups
• 1/2 cup chopped pecans or walnuts, optional

For the Lightly Crisp Cinnamon Topping

• 2 tablespoons packed light brown sugar
• 1 tablespoon old-fashioned rolled oats
• 1/2 teaspoon ground cinnamon
• 1 tablespoon chopped pecans or walnuts, optional, taken from the 1/2 cup listed above or added separately

For Serving

• Warm milk, cream, or yogurt, optional
• Additional maple syrup, optional
• Extra diced apple or toasted nuts, optional

Step-by-Step Instructions

Step 1: Heat the oven and prepare the baking dish

Place a rack in the center of the oven and preheat to 350°F. Lightly butter an 8-inch square baking dish, a 9-inch square baking dish, or a similar 2-quart casserole dish. An 8-inch dish will give you slightly thicker slices, while a 9-inch dish will bake a little faster and produce a slightly thinner casserole.

Step 2: Mix the dry ingredients

In a large mixing bowl, stir together 2 cups old-fashioned rolled oats, 1 1/2 teaspoons baking powder, 1 1/2 teaspoons ground cinnamon, 1/4 teaspoon ground nutmeg, and 3/4 teaspoon fine salt. Make sure the baking powder and spices are evenly distributed so every bite bakes up flavorful and tender.

Step 3: Whisk the wet ingredients

In a medium bowl or large liquid measuring cup, whisk together 2 cups whole milk, 2 large eggs, 1/3 cup pure maple syrup, 1/4 cup melted unsalted butter, and 2 teaspoons vanilla extract. Whisk until the eggs are fully blended and the mixture looks smooth. If the melted butter is very hot, let it cool for about 5 minutes before adding it so it does not scramble the eggs.

Step 4: Fold in the apples and nuts

Add the diced apples to the bowl of dry ingredients and toss until the apple pieces are lightly coated with the oat mixture. This helps the fruit stay evenly scattered through the casserole rather than sinking to the bottom. If using nuts, fold in 1/2 cup chopped pecans or walnuts, reserving 1 tablespoon for the topping if you would like extra crunch on top.

Step 5: Combine and transfer to the baking dish

Pour the wet mixture over the oat and apple mixture. Stir gently until all the oats are moistened and no dry pockets remain. The mixture will look loose and milky at this stage; that is exactly right. Pour everything into the prepared baking dish and use a spatula or spoon to spread the apples and oats into an even layer.

Step 6: Add the cinnamon oat topping

In a small bowl, stir together 2 tablespoons packed light brown sugar, 1 tablespoon rolled oats, and the remaining 1/2 teaspoon ground cinnamon. Sprinkle this mixture evenly over the top of the oatmeal. Add the reserved 1 tablespoon chopped nuts, if using. This topping melts slightly as it bakes, creating a lightly crisp, fragrant cinnamon crust.

Step 7: Bake until set and golden

Bake uncovered at 350°F for 38 to 42 minutes, or until the edges are lightly golden, the top looks set, and the center no longer jiggles loosely when the dish is gently nudged. A small knife inserted into the center should come out mostly clean, with moist oats clinging to it but no runny liquid.

Step 8: Rest, slice, and serve warm

Let the baked oatmeal rest for 10 minutes before slicing. This short rest allows the oats to finish absorbing moisture and helps the casserole hold together. Serve warm in squares with a splash of milk, a spoonful of yogurt, a drizzle of maple syrup, or extra diced apples and toasted nuts on top.

Pro Tips

• Use old-fashioned rolled oats: They give the best tender-but-hearty texture. Quick oats can become softer and more uniform, while steel-cut oats will not soften properly in this baking time.
• Choose apples that hold their shape: Honeycrisp, Fuji, Pink Lady, Braeburn, and Granny Smith all work well. Softer apples may break down more during baking, which is still tasty but less textured.
• Dice the apples evenly: Aim for 1/2-inch pieces so the apples become tender in the same amount of time the oats need to bake.
• Do not skip the rest time: The baked oatmeal will seem soft straight from the oven, but it firms up beautifully after 10 minutes.
• For a more dessert-like top: Add an extra 1 tablespoon melted butter to the brown sugar topping before sprinkling it over the oatmeal.

Variations

• Apple cranberry baked oatmeal: Add 1/2 cup fresh or frozen cranberries with the apples for a tart, colorful twist. Increase the maple syrup to 1/2 cup if you prefer a sweeter bake.
• Dairy-free version: Use unsweetened almond milk, oat milk, or coconut milk in place of whole milk, and swap the butter for melted coconut oil or a neutral oil.
• Apple pie style: Add 1/4 teaspoon ground ginger and 1/8 teaspoon ground cloves to the dry ingredients, then serve with vanilla yogurt or a small spoonful of whipped cream for brunch.

Storage & Make-Ahead

Store cooled baked oatmeal covered in the refrigerator for up to 4 days. Reheat individual portions in the microwave for 45 to 75 seconds, or reheat several portions covered with foil in a 325°F oven for 15 to 20 minutes. To freeze, wrap individual cooled squares tightly and freeze for up to 3 months; thaw overnight in the refrigerator before reheating. For a make-ahead option, assemble the dry ingredients and topping separately the night before, dice the apples, and whisk the wet ingredients in a covered container. In the morning, combine everything, pour into the baking dish, add the topping, and bake as directed. For the best texture, avoid letting the fully mixed oatmeal sit overnight, as the oats will absorb too much liquid before baking.

Nutrition (per serving)

Approximate nutrition per serving, based on 8 servings and made with whole milk, butter, apples, and pecans: 285 calories, 10 g fat, 3.5 g saturated fat, 42 g carbohydrates, 5 g fiber, 18 g sugars, 8 g protein, and 300 mg sodium. Nutrition will vary depending on the type of milk, apples, nuts, and toppings used.