Oatmeal Breakfast Casserole Recipe
Introduction
This Oatmeal Breakfast Casserole is a warm and comforting way to start your day. Packed with apples, nuts, and wholesome oats, it’s a nutritious, make-ahead breakfast that the whole family will love.

Ingredients
- 3 cups diced apple (about 2 large or 3 small apples, your favourite variety)
- 2 tablespoons ground flaxseed
- ¼ cup water
- 3 cups old fashioned rolled oats (not instant or steel cut, gluten-free if needed)
- 1 cup chopped walnuts or pecans
- ½ cup raisins or sultanas
- 2 teaspoons baking powder
- 2 teaspoons cinnamon
- ¼ teaspoon ground nutmeg
- 3 tablespoons chia seeds
- 3 tablespoons hemp seeds (optional)
- ¼ teaspoon sea salt
- 3½ cups unsweetened almond milk
- ½ cup maple syrup
- 1 tablespoon vanilla extract
- 2 tablespoons coconut sugar (optional)
Instructions
- Step 1: Preheat the oven to 350°F.
- Step 2: Chop the apples and transfer them to a large bowl filled with water and a squeeze of lemon to prevent browning.
- Step 3: In a small bowl, mix the ground flaxseed and water. Set aside for 5 minutes to thicken.
- Step 4: In a large bowl, combine the rolled oats, chopped nuts, raisins, baking powder, cinnamon, nutmeg, chia seeds, hemp seeds, and sea salt.
- Step 5: In a separate bowl or glass measuring cup, mix the almond milk, maple syrup, and vanilla extract. Add the thickened flaxseed mixture and stir to combine.
- Step 6: Pour the wet ingredients into the dry ingredients and mix thoroughly with a spatula.
- Step 7: Drain the apples well using a colander, then fold them into the oat mixture. The batter will be loose – this is normal.
- Step 8: Transfer the mixture to a 9×9 inch casserole dish or similar size. Cover with tinfoil and bake for 50 minutes.
- Step 9: Remove the tinfoil, sprinkle coconut sugar on top if using, and bake for an additional 20 minutes until golden and set.
- Step 10: Let the casserole sit for at least 10 minutes before slicing or serving. Top with almond caramel, nut butters, maple syrup, extra nuts, or fresh berries as desired.
Tips & Variations
- Soak the rolled oats overnight to make the casserole even creamier and reduce baking time slightly.
- Swap apples for pears or add diced sweet potato for a seasonal twist.
- Use chopped pecans instead of walnuts for a milder nutty flavor.
- Add a handful of shredded coconut or pumpkin seeds for extra texture.
- If you prefer a sweeter casserole, increase the maple syrup by 2 tablespoons or add a sprinkle of brown sugar.
Storage
Store leftover casserole in an airtight container in the refrigerator for up to 4 days. To reheat, warm individual portions in the microwave or in a low oven until heated through. This casserole also freezes well; thaw overnight in the fridge before reheating.
How to Serve

Serve this delicious recipe with your favorite sides.
FAQs
Can I use a different type of milk?
Yes, you can substitute almond milk with any plant-based milk such as oat, soy, or coconut milk. Dairy milk works as well if you’re not avoiding dairy.
Is this casserole gluten-free?
It can be, as long as you use certified gluten-free rolled oats and ensure your other ingredients are gluten-free. Always check labels if you have a gluten intolerance or allergy.
PrintOatmeal Breakfast Casserole Recipe
This wholesome Oatmeal Breakfast Casserole is a hearty and nutritious start to your day, combining rolled oats, apples, nuts, and seeds baked to perfection. Naturally sweetened with maple syrup and lightly spiced with cinnamon and nutmeg, it offers a warming and comforting breakfast option that is both gluten-free (when using gluten-free oats) and vegan. Perfect for batch cooking and serving warm, topped with nut butters, fresh berries, or almond caramel for extra indulgence.
- Prep Time: 15 minutes
- Cook Time: 1 hour 10 minutes
- Total Time: 1 hour 25 minutes
- Yield: 8 servings 1x
- Category: Breakfast
- Method: Baking
- Cuisine: American
- Diet: Gluten Free
Ingredients
Fruit and Nuts
- 3 cups diced apple, your favourite variety (about 2 large or 3 small apples)
- 1 cup chopped walnuts or pecans
- ½ cup raisins or sultanas
Dry Ingredients
- 3 cups old fashioned rolled oats (not instant or steel cut; gluten-free if needed)
- 2 teaspoons baking powder
- 2 teaspoons cinnamon
- ¼ teaspoon ground nutmeg
- 3 tablespoons chia seeds
- 3 tablespoons hemp seeds (optional)
- ¼ teaspoon sea salt
- 2 tablespoons coconut sugar (optional)
Wet Ingredients and Mixers
- 2 tablespoons ground flaxseed
- ¼ cup water
- 3½ cups unsweetened almond milk
- ½ cup maple syrup
- 1 tablespoon vanilla extract
Instructions
- Preheat Oven: Set your oven to 350°F (175°C) to warm up while you prepare the casserole mixture.
- Prepare Apples: Chop the apples into small dice and place them in a large bowl filled with water and a squeeze of lemon juice to prevent browning.
- Make Flax Egg: In a small bowl, combine the ground flaxseed with ¼ cup water and let it thicken for 5 minutes to create a flax egg substitute for binding.
- Combine Dry Ingredients: In a large mixing bowl, stir together the rolled oats, chopped nuts, raisins, baking powder, cinnamon, nutmeg, chia seeds, hemp seeds (if using), and sea salt.
- Mix Wet Ingredients: In a separate bowl or measuring cup, whisk together the almond milk, maple syrup, and vanilla extract, then add the thickened flax mixture and stir to combine.
- Combine Wet and Dry: Pour the wet ingredients into the dry ingredients bowl and mix thoroughly with a spatula until evenly incorporated.
- Add Apples and Mix: Drain the apples well in a colander and fold them into the oat mixture. The batter will appear loose, which is expected.
- Transfer to Baking Dish: Pour the mixture into a 9×9 inch casserole dish or a similarly sized baking pan, smoothing the top as needed.
- Initial Bake: Cover the casserole loosely with aluminum foil and bake in the preheated oven for 50 minutes to allow it to set.
- Add Coconut Sugar and Continue Baking: Remove the foil, sprinkle the optional coconut sugar evenly over the top, and bake uncovered for an additional 20 minutes until golden and firm.
- Cool and Serve: Take the casserole out of the oven and let it rest for at least 10 minutes before slicing or spooning out servings. Enjoy topped with almond caramel, nut butters, extra maple syrup, nuts, or fresh berries as desired.
Notes
- Use gluten-free oats to keep this recipe gluten-free.
- The flaxseed mixture works as an egg substitute, making this casserole vegan-friendly.
- Allowing the casserole to rest after baking helps it firm up and makes slicing easier.
- Optional coconut sugar adds a caramelized sweetness and slight crunch on top.
- Feel free to swap walnuts or pecans with your preferred nuts or seeds for variation.
- This casserole can be refrigerated and reheated for a quick breakfast throughout the week.
Keywords: oatmeal casserole, breakfast casserole, baked oats, gluten-free breakfast, vegan breakfast, maple syrup, apples, rolled oats, chia seeds

