Baked Blueberry Oatmeal

This wholesome lemon blueberry baked oatmeal is a great way to kick-off your day! Our family has made this easy baked oatmeal recipe countless times over the past couple of years, with great results every time. Lemon blueberry baked oats is the best combination of sweet and tart flavors, making a great breakfast for lazy weekend mornings or as a meal prep breakfast to enjoy during the week. 

The Midwest winters are LONG, and I’m always in the market for warm and cozy breakfast recipes that are both nutritious and good for storing in the fridge for the week to make our mornings easier. We’ll often prep an egg bake (like my broccoli, cheese, and chicken sausage egg casserole) for the week, but sometimes you just want something sweet.

And while I’d love to enjoy a slice of brioche French toast bake everyday, I like to keep that for special occasions. So I created this lemon blueberry baked oatmeal recipe! The classic combination of lemon and blueberry is a winner with the oatmeal and this recipe is ridiculously easy to make. The result? A lemon blueberry oatmeal bake that’s fluffy yet slightly chewy with a golden brown top.  

This delicious blueberry lemon baked oatmeal will definitely be in our family’s breakfast rotation often, and I hope it will be in yours too!

Blueberry Baked Oatmeal Ingredients

• Milk. My family uses skim or 2% dairy milk (whatever we happen to have in the fridge). If desired, you can use your favorite non-dairy milk too.
• Eggs. In addition to adding a little protein, the eggs’ primary role in our recipe is to help hold our oatmeal together, resulting in a baked oatmeal that can slice like a cake or a loaf.   
• Pure maple syrup. No icky fake stuff allowed! 100% pure maple syrup sweetens the blueberry baked oatmeal, adding a warm and rich sweetness to our breakfast bake. 
• Salted butter. Butter adds moisture and a savory flavor to our bake.
• Unsweetened applesauce. In addition to adding sweetness, applesauce provides more moisture to the oatmeal. Like the eggs, applesauce also acts like a binder to help hold our baked oatmeal together.
• Lemon juice and lemon zest. The combination of fresh lemon juice and fresh lemon zest produces a wonderfully bright lemon flavor. To obtain lemon zest, use the smallest holes on your grater or microplane to grate the lemon skin. Stop grating once you reach the bitter white pith. 
• Old-fashioned oats (aka rolled oats). Old fashioned rolled oats give our baked oatmeal the perfect texture! I do not recommend subbing out the type of oats in this recipe as the texture and baking time could change drastically. You can learn more about why this is in my post on everything you need to know about oats.  
• Baking powder. Baking powder helps to create a baked oatmeal that is light and fluffy.
• Vanilla extract. Vanilla extract adds depth of flavor and richness to our baked blueberry lemon oatmeal.
• Salt. Salt acts as a flavor enhancer and also helps to balance the sweetness in this recipe. You don’t need very much for the desired effect.
• Fresh or frozen blueberries. Fresh blueberries are a great option when they’re in season, but when the fresh berries at the store aren’t looking so great frozen blueberries are the perfect option. I personally love and use frozen wild blueberries for this recipe! Frozen wild blueberries, also known as high-bush blueberries, are smaller and usually have a more intense blueberry flavor. I often prefer frozen because I can always have them on hand and they don’t even need to be thawed beforehand! So convenient! 
• Optional toppings. Top lemon blueberry baked oatmeal with extra maple syrup, a dollop of vanilla Greek yogurt, chia seeds, or chopped nuts (I like to use pecans, walnuts, or sliced almonds). You can also toss on some additional blueberries if you’d like!        

See recipe card below for a full list of ingredients and measurements.

How to Make Baked Oatmeal with Blueberries

Preheat your oven to 350°F and spray your square baking pan (either an 8×8 or 9×9) with nonstick cooking spray. 

Add your wet ingredients (the milk, eggs, maple syrup, melted butter, applesauce, vanilla extract, and lemon juice) to a large mixing bowl and mix together.

Add in the lemon zest, baking powder, and salt and whisk to combine with the wet ingredients.

Add the dry oatmeal to the bowl.

Stir into the wet ingredients.

Gently stir in the blueberries (it’s ok if it turns a little purple – this happens more often with frozen blueberries).

Carefully pour the blueberry oatmeal mixture into the greased baking dish.

Spread the oatmeal mixture into an even layer. 

Bake for 35 minutes, or until the center of the oatmeal bake appears to be almost set and with edges that are golden brown.

Allow the lemon and blueberry baked oatmeal to cool for at least 5 minutes before serving. Enjoy by spooning or slicing the baked lemon blueberry oatmeal onto a plate and serve with your desired toppings. 

Possible Dietary Restrictions?

This easy baked oatmeal recipe is vegetarian as written. It is also gluten free as written, however, oats have a high likelihood of gluten contamination during processing. So if you’re serving this to someone with celiac, be sure to check the label and select rolled oats that are certified to be gluten free.

You can also make this into a vegan and dairy free oatmeal bake with a few substitutions. To do so, select a non-dairy milk (like unsweetened almond milk, oat milk, or soy milk) and replace the salted butter with oil (like coconut oil) or a plant-based butter. For a vegan baked oatmeal, you will also need to replace the eggs with flax eggs (or vegan egg substitute of choice). You can make a flax egg by mixing 1 tablespoon of ground flax with 2 ½ tablespoons of water and letting the mixture rest for 5 minutes to thicken.     

How to Store Baked Oatmeal

Does baked oatmeal need to be refrigerated?

Leftover lemon blueberry baked oats can be stored in the fridge for up to 5 days. Be sure to let the baked oats cool to room temperature before wrapping the leftovers tightly with plastic wrap or storing it in airtight container and placing it in the fridge.

Can you freeze Baked Oatmeal?

Lemon blueberry baked oatmeal is freezer-friendly! Wrap cooled, individual portions in plastic wrap and place them into a labeled freezer-safe zip top bag. Freeze baked oatmeal for up to 3 months. When ready to enjoy, allow to thaw in the fridge overnight before reheating. 

How to Reheat Baked Oatmeal

Reheat individual portions of the baked oatmeal in the microwave. Begin by heating your slice in short intervals (for example, 30-second intervals) until your desired warmth is reached. Once you’ve reheated one slice, you’ll have a better idea of how long your microwave needs to warm up your baked oatmeal.