Easy Blueberry Lemon Baked Oatmeal

Bright lemon flavor and bursting with berries, this Easy Blueberry Lemon Baked Oatmeal uses rolled oats, fresh or frozen blueberries and other simple ingredients for a quick to make, freezer-friendly, delicious meal prep breakfast.

Stovetop, Instant Pot, overnight, baked, rolled, steel cut, quick oats… oatmeal recipe possibilities are nearly endless, which is why oats make such a great meal prep option. I’m positive there’s an oatmeal recipe out there for you!

This time, I baked the oats in the oven. In a similar style as my PB&J Pancake Bake, we bake the whole thing at one time, instead of making yourself an oatmeal breakfast every morning of the week. Cook once, eat lots of times!

In this recipe, I focused on my love of the blueberry lemon flavor combo. I love this recipe because it tastes great cold from the fridge, or reheated with some milk and maple syrup on top. I hope you enjoy it!

What are the ingredients in this Easy Blueberry Lemon Baked Oatmeal?

This recipe uses simple ingredients that should be easy to find at the grocery store, if you don’t already have them on hand in the fridge or pantry. Here are the ingredients I used and a little info for each:

• large eggs – The eggs function as the binder in this recipe. They are what hold everything together!
• milk of choice – Use your milk of choice or whatever you have on hand. Dairy or non-dairy milk will both work.
• applesauce – Adding some applesauce to this recipe helps keep the baked oatmeal moist instead of dry and crumbly.
• pure maple syrup – This is my sweetener of choice, I love the maple flavor! You could also use the same amount of granulated sugar.
• unsalted butter – Butter adds delicious flavor and some fat to help bind and moisten.
• vanilla extract – A classic background flavor that’s a must in baked goods.
• large lemon – Find a big lemon for this one! First zest the lemon completely (you can do this directly into the pan as pictured), then squeeze the halves to get the lemon juice.
• rolled oats – Also known as old-fashioned oats! These oats are rolled flat, but not processed as much as quick oats or instant oats. Do not use steel cut oats for this recipe!
• ground cinnamon – I’ve found that blueberry and cinnamon are a fabulous flavor combo (check out my blueberry cinnamon smoothie!). Don’t skip!
• baking powder – Baking powder helps the oatmeal puff up a bit while baking.
• chia seeds – These are technically optional as they don’t change the taste or texture in any way, but I love adding some chia seeds for the little extra nutritional boost. I almost always have them on hand anyway for chia pudding!
• salt – Just a small amount of salt helps bring out all the sweet flavors in this baked oatmeal!
• blueberries – Blueberries are the star in this recipe! You can use fresh or frozen blueberries, depending on what’s more available or in season near you.

How do you make this Easy Blueberry Lemon Baked Oatmeal?

Making this recipe involves very little hands on time, and very few dirty dishes! I like to mix everything directly in the casserole dish. If you’re worried about sticking, feel free to grease the pan well and mix all the ingredients in a separate bowl, then transfer and bake.

After gathering ingredients, preheat the oven to 375F. Whisk the eggs together in a 9×13 casserole dish (or another mixing bowl if you prefer), using a fork or a whisk (1 in the numbered photos below).

Next, add milk, applesauce, maple syrup (2), melted butter, vanilla extract, lemon zest (4), and lemon juice (5). Use a whisk or large mixing spoon to stir until combined. I stirred before and after zesting – order doesn’t really matter here!

After all the wet ingredients have been stirred together, it’s time to add the dry ingredients. Add the rolled oats (6), ground cinnamon, baking powder, chia seeds and salt on top of the wet ingredients (7). Gently mix everything with a rubber spoon spatula until combined.

Finally, add the blueberries and gently mix to combine one last time (8). Top with additional blueberries if you want that fancy polka dot top look (9). Bake the oatmeal uncovered for 28-32 minutes, or until the edges are browning and the top appears set.

Let the oatmeal bake cool for at least 5 minutes before cutting into 8 servings. If you cut it too early, it will be too hot and might start to crumble. I like to top with a little more maple syrup, whipped cream and more fresh berries when serving.

How to turn this baked oatmeal into oatmeal cups:

To turn this baked oatmeal into cups, grease a 12-count muffin tin with cooking spray, or use silicone baking cups. Make recipe as written in a separate mixing bowl, then divide batter between the 12 muffin wells.

Bake at 350F for 20-23 minutes, or until the edges are golden brown and a toothpick inserted around the edge comes out clean.

For some yummy oatmeal based baked cups, try my Peanut Butter and Jelly Baked Oatmeal Cups, or my Oatmeal Applesauce Blender Muffins.

Testing notes for this Easy Blueberry Lemon Baked Oatmeal recipe:

While testing this recipe, here are a couple things I noticed:

• I have made this recipe directly in the casserole dish multiple times and not had any issues with the oatmeal sticking to the pan. However, I know not all pans are the same. If you’re worried about sticking, feel free to grease the pan well and mix all the ingredients in a separate bowl, then transfer and bake.
• Applesauce vs. Banana – I tested this recipe with one mashed banana instead of the 1/2 cup applesauce. Overall, we preferred the applesauce version better.
• The lemon zest is necessary for a strong, noticeable lemon flavor.
• This baked oatmeal tastes delicious directly from the fridge! Like a cold breakfast bread pudding, but made with oatmeal.

How do you meal prep this Easy Blueberry Lemon Baked Oatmeal?

There are a couple ways to save time by preparing this recipe ahead. Here are some options:

1. Complete prep: Make the recipe as written, then portion and store leftovers in individual containers or wrapped tightly in plastic wrap or foil.
2. Enjoy now & later: Enjoy this baked oatmeal fresh from the oven for breakfast today, then later in the week, enjoy it cold from the fridge as leftovers.
3. Complete prep & freeze: If eight portions is too many for your household to enjoy in 5 days, feel free to freeze some of the portions. Wrap tightly in plastic wrap, aluminum foil, a freezer-safe bag, or some combination or these. Label and store in the freezer for up to 3 months for best quality.

What should you serve with this recipe?

This recipe makes a delicious meal on it’s own, but it could also be served with some breakfast sausage or eggs on the side. I think it would go well at a brunch or served with most other breakfast foods.

Alternative customization ideas:

Sally’s original recipe for 1 Bowl Baked Oatmeal says you can swap the berries (or in the case of my version, blueberries and lemon) for just about anything, including “chopped banana, apple, peaches, pears, raisins, dried berries, chocolate chips, or even a spoonful of your favorite nut butter”.

How to store prepared Blueberry Lemon Baked Oatmeal:

Store leftovers in an airtight container in the fridge for up to 5 days. You can store this in a glass container with lid or in a Stasher style silicone food bag.

How to freeze prepared Blueberry Lemon Baked Oatmeal:

Wrap tightly in plastic wrap, aluminum foil, a freezer-safe bag, or some combination or these. Label and store in the freezer for up to 3 months for best quality.

How to reheat Blueberry Lemon Baked Oatmeal:

You can definitely eat this oatmeal cold from the fridge (I love it cold! + easy to transport).

Reheat in the microwave for about 90 seconds or until steaming hot. You may want to add some additional milk drizzled over the top so it doesn’t dry out.