Blueberry Baked Oatmeal with Streusel Topping

Blueberry baked oatmeal is the kind of breakfast that feels like a treat but is sturdy enough to fuel your whole morning. It’s a soft, custardy oatmeal studded with juicy blueberries, finished with a crunchy brown sugar topping.

Make it on Sunday and have a warm square waiting for you every weekday. No fuss, no standing over the stove.

Why This Baked Oatmeal Stays in My Breakfast Rotation

I keep coming back to this recipe because it tastes like a blueberry muffin without the extra steps. The oatmeal base is tender and set, not at all dry, and the berries burst into little jammy pockets.

The streusel on top stays crisp even after a couple of days in the fridge, which is a small miracle. It makes weekday mornings feel a little more special.

And because it’s baked in one dish, cleanup is just a single pan. I can pull it together while the coffee drips.

Ingredients

• 2 cups rolled oats: old-fashioned oats work best; quick oats will turn mushy
• 1 1/2 cups milk: any milk, dairy or unsweetened non-dairy
• 2 large eggs
• 1/4 cup maple syrup: or honey, but maple adds a deeper flavor
• 2 tablespoons melted butter: or melted coconut oil
• 1 teaspoon vanilla extract
• 1 teaspoon baking powder
• 1/2 teaspoon fine sea salt
• 1 1/2 cups fresh or frozen blueberries: no need to thaw if frozen
• 1 teaspoon lemon zest: (optional)

Streusel:

• 1/4 cup all-purpose flour
• 1/4 cup packed brown sugar
• 2 tablespoons cold butter, cut into small pieces
• 1/2 teaspoon ground cinnamon
• 1/4 cup chopped pecans or walnuts: (optional)

Variations / Substitutions

• Dairy-free: Use unsweetened oat or almond milk and swap the butter for melted coconut oil or a vegan butter. For the streusel, use cold vegan butter.
• Nut-free: Omit the optional nuts and add an extra tablespoon of flour to the streusel.
• Sweetener swap: Replace maple syrup with honey, agave, or brown sugar dissolved in a couple tablespoons of warm water.
• Spice it up: Add 1/4 teaspoon nutmeg or cardamom along with the cinnamon for a warmer flavor.
• Berry mix: Toss in raspberries or blackberries with the blueberries, or use diced peaches in summer.

If you want something you can grab straight from the fridge, try my Blueberry Oatmeal Cups.

How to Make Blueberry Baked Oatmeal

Step 1: Whisk the Wet Ingredients

Preheat your oven to 375°F (190°C) while you get started. In a large bowl, whisk together the 1 1/2 cups milk, 2 large eggs, 1/4 cup maple syrup, 2 tablespoons melted butter, and 1 teaspoon vanilla extract until smooth. Add the 1 teaspoon baking powder and 1/2 teaspoon salt and whisk again.

You want the eggs fully beaten so there are no streaks. The mixture will look thin and slightly frothy, that’s exactly right.

Step 2: Fold in the Oats and Blueberries

Pour the 2 cups rolled oats into the wet mixture and stir to combine, then grate in the 1 teaspoon lemon zest if you’re using it. Gently fold in the 1 1/2 cups blueberries, taking care not to crush them.

The oats will look like they’re swimming in liquid, but don’t worry, they’ll soak it all up as it bakes. The blueberries should be barely incorporated, not bleeding.

Step 3: Top with Streusel and Bake

In a small bowl, mix the 1/4 cup flour, 1/4 cup brown sugar, and 1/2 teaspoon cinnamon. Add the 2 tablespoons cold butter pieces and use your fingers to work them in until the mixture looks like damp sand with pea-sized clumps. Stir in the 1/4 cup chopped nuts if you’re using them.

Scrape the oatmeal mixture into a greased 9-inch square baking dish and spread it even. Sprinkle the streusel over the top in an even layer. Bake for 40 to 45 minutes, until the top is golden brown and a knife poked in the center comes out clean. The edges will pull away from the pan, and your kitchen will smell wonderfully toasty.

Step 4: Slice and Serve Warm

Let the baked oatmeal rest for at least 10 minutes before you slice it; this helps it set so you get clean squares. Cut it into 9 pieces and serve warm.

A drizzle of maple syrup or a dollop of yogurt on top takes it to the finish line. The top will be crunchy, the middle soft and custardy, with pops of blueberry in every bite.

A Few Tips for the Best Baked Oatmeal

• Make it the night before: Assemble the oatmeal mixture (without the streusel), cover, and refrigerate overnight. In the morning, sprinkle on the streusel and bake. You may need to add 5 minutes to the bake time.
• Double it for a crowd: Use a 9×13-inch pan and double all ingredients. The bake time will increase (see table below).
• Cool completely for storage: For the cleanest slices when storing, let the oatmeal cool completely before cutting. It firms up and won’t crumble.
• Nut-free version: The streusel is just as good without nuts; simply use an extra tablespoon of flour to maintain the crumb.

If you double the recipe, use this guide for baking time:

Keeping It Fresh

• Refrigerate: Store cooled squares in an airtight container in the fridge for up to 5 days.
• Reheating: Warm individual squares in the microwave for 30 to 45 seconds, or reheat in a 300°F (150°C) oven for 10 minutes to re-crisp the top.

What to Serve With Blueberry Baked Oatmeal

A spoonful of thick Greek yogurt adds tang and extra protein that balances the sweet streusel. A drizzle of warm maple syrup makes it feel like a special weekend breakfast. Fresh berries on the side brighten everything up and add a little extra juiciness.

Frequently Asked Questions

Can I use steel-cut oats?

No, steel-cut oats need much longer cooking and will stay hard and gritty in this recipe. Stick with old-fashioned rolled oats for the best texture.

Why did my baked oatmeal turn out soggy?

Sogginess usually comes from using quick oats or too much liquid. Stick with old-fashioned rolled oats and measure the milk carefully.

Can I add protein powder?

Yes, mix 1/4 cup vanilla protein powder into the dry ingredients (oats) and add an extra 2 tablespoons of milk to keep the oatmeal moist.

Can I skip the streusel?

Absolutely, the oatmeal base is still flavorful on its own. The top will be a little softer, but you’ll still get those jammy blueberry pockets.

Blueberry Baked Oatmeal Recipe

Print Recipe Pin Recipe

Prep Time 10 minutes mins

Cook Time 42 minutes mins

Total Time 52 minutes mins

Servings: 9 servings

Calories: 223

Ingredients Method Notes

Ingredients

  

• 2 cups rolled oats
• 1 1/2 cups milk
• 2 large eggs
• 1/4 cup maple syrup
• 2 tablespoons melted butter
• 1 teaspoon vanilla extract
• 1 teaspoon baking powder
• 1/2 teaspoon fine sea salt
• 1 1/2 cups fresh or frozen blueberries
• 1 teaspoon lemon zest (optional)
• 1/4 cup all-purpose flour
• 1/4 cup packed brown sugar
• 2 tablespoons cold butter, cut into small pieces
• 1/2 teaspoon ground cinnamon
• 1/4 cup chopped pecans or walnuts (optional)

Method

 

1. Preheat oven to 375°F (190°C). In a large bowl, whisk milk, eggs, maple syrup, melted butter, and vanilla until smooth. Whisk in baking powder and salt.
2. Stir in oats and lemon zest. Gently fold in blueberries.
3. In a small bowl, mix flour, brown sugar, and cinnamon. Work in cold butter with fingers until crumbly, with pea-sized clumps. Stir in nuts if using.
4. Spread oatmeal mixture into a greased 9-inch square baking dish. Sprinkle streusel on top. Bake 40–45 minutes until golden and a knife inserted in center comes out clean. Cool 10 minutes, then slice and serve warm.

Notes

If using frozen blueberries, no need to thaw them first; they’ll cook just as well. For a make-ahead option, assemble the oatmeal mixture the night before and refrigerate, then add streusel and bake in the morning, adding about 5 minutes to the bake time.