Blueberry Banana Baked Oatmeal: Warm Breakfast Casserole Recipe

Start your mornings with a warm serving of banana blueberry baked oatmeal topped with crunchy walnuts — an easy, wholesome breakfast that reheats beautifully all week. This plant-based, vegan-friendly recipe uses no eggs or dairy: just rolled oats, ripe banana, fresh blueberries, cinnamon, creamy oat milk, a touch of brown sugar, and toasted walnuts for texture. It’s simple to prepare, nourishing, and full of fiber and antioxidants.

Why You’ll Love This Vegan Baked Oatmeal

• Delicious. Warm, comforting oats flavored with cinnamon, brown sugar, ripe banana, and juicy blueberries make a satisfying breakfast.
• Meal Prep Friendly. Baked in a single dish, this recipe yields about nine servings that reheat quickly for busy mornings.
• Nutritious. Made with oats, flaxseed, fruit, and nuts, it provides fiber, healthy fats, and steady energy to keep you full through the morning.

What You’ll Need

Ingredients (overview)

• Old fashioned rolled oats
• Milk of choice — creamy oat milk recommended
• Granulated sugar and brown sugar (or swap maple syrup or agave for granulated sugar)
• Flax egg (ground flax + water) — or substitute 2 eggs
• Fresh blueberries (or dried)
• Chopped toasted walnuts (or pecans/almonds)
• Ground cinnamon, vanilla extract, baking powder, and a pinch of salt

Substitutions and Variations

• Flax “eggs” make this egg-free. To use real eggs, replace the flax mixture with 2 eggs and add ¼ cup more milk.
• Any dairy or plant milk works; creamier milks yield thicker oatmeal. Oat milk gives a rich texture.
• Swap granulated sugar for maple syrup or agave for a different sweetness and flavor.
• Use a mix of fresh berries (raspberries, blackberries) instead of blueberries. Frozen berries may increase moisture and baking time.
• Replace walnuts with pecans or almonds, or omit nuts for a nut-free option.

How to Make Banana Blueberry Baked Oatmeal

Follow these straightforward steps for a hands-off, cozy breakfast.

Printable recipe card below.

1. Make the flax egg by combining ground flax seed and water. Let it sit until thickened, about 10 minutes.
2. Whisk milk, granulated sugar, vanilla, and the flax mixture in a large bowl.
3. Add oats, cinnamon, baking powder, salt, walnuts, and mashed banana. Gently fold in blueberries.
4. Pour the mixture into a greased 8-inch baking dish and bake at 350°F until the center is just slightly jiggly, about 40–55 minutes.
5. Remove from the oven and evenly sprinkle brown sugar across the top.
6. Set the oven to broil and broil about 4 inches from the heat until the sugar bubbles and browns slightly—watch carefully (1–2 minutes).
7. Let the baked oatmeal rest about 10 minutes to firm up before serving. Reheat portions as needed during the week.

Serving Suggestions

• Serve warm with a drizzle of milk.
• Sweeten to taste with extra brown sugar or maple syrup.
• Top with extra nuts or fresh berries for added texture and color.

Kori’s Tips

• To make a larger batch, double the recipe and bake in a 13 x 9″ pan; increase baking time by about 10 minutes or until set.
• If using real eggs, add ¼ cup extra milk to the batter.
• Adjust sweetness to your preference. The recipe is intentionally mildly sweet so everyone can finish with their preferred topping.

Storage and Reheating Tips

• Leftovers: Refrigerate covered for up to 5 days.
• Reheating: Warm individual portions in the microwave until heated through. Add a splash of milk to rehydrate if needed.

Save this recipe for later — it’s an easy weeknight or weekend breakfast to prep ahead.

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Banana Blueberry Baked Oatmeal

Kori’s Tips

Nutrition