Healthy Baked Oatmeal You Can Freeze and Reheat

How many times have you opened a packet of instant oatmeal for breakfast because you didn’t have time for anything else? I’ve been there until I figured out that I could actually make my oatmeal ahead of time and either keep it in the fridge or freeze some for later.

So I learned how to make baked oatmeal that could be frozen – and, trust me, it took some trial and error to get it exactly right. The amount of liquids you use really does matter!

The fun part about this baked oatmeal recipe is that it’s easy to customize to your liking. Check out some of the variations below for sweet, savory, and even spicy oatmeal!

How to Make Baked Oatmeal

Basic baked oatmeal does take a few more ingredients than making it on the stovetop or in the microwave. It does have some similarities to a casserole in that you’ll need a good casserole dish, and one of the ingredients needs to be a binder, which is where the eggs come in.

My personal favorite is a glass casserole dish that you can also put in the freezer once it cools down. (You just want to make sure it’s completely cooled down before you freeze it – rapid temperature changes can be tough on glass dishes!)

Method for Baked Oatmeal:

In a large bowl, add your butter and melt it in the microwave. Then add the sugar and eggs and mix together really well. I prefer to use a sturdy wooden spoon instead of a mixer because I think it comes out better.

Next, add in the baking powder, teaspoon vanilla extract, cinnamon, and salt, and combine. Stir in the milk and oats until everything is really well combined.

Pour into a greased 9×13 baking dish and bake at 350 degrees for about 35-45 minutes or until it’s set in the middle and golden brown.

Nutrition Information for Baked Oatmeal

The above baked oatmeal recipe makes for a very healthy make-ahead breakfast, as the below nutritional information shows. I calculated this nutritional information* on VeryWellFit’s nutrition calculator.

*Disclaimer: This is a rough estimate for nutrition information based on the recipe as shown and can change based on the exact ingredients used.

• 249 Calories
• 7 Grams Fat
• 3.1 Grams Saturated Fat
• 72 Milligrams Cholesterol
• 1.7 Grams Sodium
• 39.7 Grams Carbohydrates
• 7.3 Grams Dietary Fiber
• 8.6 Grams Sugar
• 6.1 Grams Protein
• 8 mcg Vitamin D (41% Recommended Daily Value)
• 846 mg Calcium (65% Recommended Daily Value)
• 3 mg Iron (19% Recommended Daily Value)
• 1.865 Grams Potassium (40% Recommended Daily Value)

…My instant oatmeal has fewer calories, though!

You’re right, I looked it up, and Quaker Instant Oatmeal does tend to be lower calorie and lower sodium per packet compared to one serving of this baked oatmeal. However, it also has less filling protein, less dietary fiber, and less valuable nutrients like Vitamin D, calcium, iron, and potassium.

Also, I’ll let you in on a little secret: I’ve sometimes cut the salt in half when making this baked oatmeal recipe because I was going for one of the sweeter variations, like adding fresh fruit or a bit of honey.

According to WebMD, if you adjust for portions, 1/3 cup of uncooked steel-cut oats typically has more fiber (5 grams), more protein (6 grams), and a roughly comparable number of Calories (170 Calories) when compared to one packet of Quaker Instant Oatmeal. Plus, that 1/3 cup of steel-cut oats typically has no preservatives or added “natural flavors”.

Nothing against Quaker Instant Oatmeal, but I’m particularly fond of using steel-cut oats in my make-ahead baked oatmeal!

Tips for Making Baked Oatmeal

You can store leftovers in the fridge for about 4-5 days. Just reheat when you’re ready to eat it, and then pour milk over the hot oatmeal. Sometimes I like to break up the oatmeal and mix it in with the milk before reheating so it absorbs the milk. Just keep an eye on it so it doesn’t bubble over while reheating.

If you have time in the morning, you can mix this up the night before and store it in the fridge overnight, and then bake it for 35-45 minutes in the morning.

It’s possible to use regular or “quick” oats. However, whenever I make baked oatmeal ahead of time, I prefer to use steel-cut or “Irish” oats. That’s the fun part about meal prep for breakfast. I don’t have to choose between convenience and using the type of oats I prefer when I’m in a hurry in the morning.

You may sometimes have to adjust the amount of liquids you use to get the consistency you want or to avoid making a mess. If you add milk when reheating your oatmeal, you’ll want to avoid adding too much or too little to keep it from bubbling over in the microwave or keep it from getting all dry and cakey. (That’s the really tricky part about oatmeal – adding too little liquid can be as bad as adding too much!)

Going low-sodium? You might be able to get away with adjusting the salt to your taste. It’s only important for some chemical reactions for texture and flavor when baking anything.

Variations for Baked Oatmeal

In fact, it’s really easy to customize oatmeal to your liking. The variations below are some of my favorites.

Fresh Fruit

I like to stir in some fresh fruit after I’ve baked or reheated the oatmeal and just before serving. My personal favorites are diced apples, peaches, banana slices, strawberry slices, blueberries, and raspberries.

Different Spices

You could get away with leaving out the cinnamon if you don’t like cinnamon. Alternatively, you can create a “pumpkin spice” variation by adding a little nutmeg, ginger, allspice, and cloves to the cinnamon.

Peanut or Almond Butter

A tablespoon of peanut butter or almond butter and a tablespoon of your favorite jelly can add a nutty-sweet twist to your oatmeal. I also sometimes like to add almond slivers to my oatmeal.

Add in More Breakfast Elements

For a savory version, leave out the cinnamon and add your favorite savory breakfast ingredients. I like to add a fried egg and some cheddar cheese when I feel like having a savory breakfast bowl.

• Sautéed veggies like mushrooms, green peppers, and onions make good additional healthy savory additions. Bite-sized sausage pieces can go well with the green peppers and onions.
• If you’re feeling adventurous and want to add a bit of spice, a dash of sriracha is good.

If you have a favorite variation for oatmeal, feel free to leave a comment below. We’d love to see it!

Substitutions for Baked Oatmeal Ingredients

I’ve sometimes stirred in some almond or oat milk instead of dairy when serving this baked oatmeal if that’s what I had on hand.

Flax eggs work in the place of regular eggs if you’re going egg-free.

Not into oats? While I haven’t found a good substitute for oats in this particular recipe yet, we do have a tasty buckwheat porridge recipe that you can make in the crockpot.

How to Freeze Baked Oatmeal

You have a couple of options when you’re freezing baked oatmeal, and I’ve tried them all with lots of success. Learn how to freeze oatmeal for a quick, easy breakfast.

1. Pour your batter into smaller pans (square foil pans or foil pie plates). Cover with plastic wrap, and then put the entire pan in a freezer bag. This method makes it possible for the oatmeal to last longer in the freezer.
2. You can also freeze the already-baked oatmeal pretty quickly after baking it. Let it cool in the casserole dish, and then cut it into squares. Wrap each square individually in plastic wrap and then freeze. Friends of mine who live alone say they prefer this method so they don’t have to eat too much of it at once or think about popping it in the oven later.
3. For extra protection against freezer burn, put the individual squares of oatmeal in airtight containers that are just big enough to hold them. I like to use these meal prep containers for any meals I make ahead to freeze.

When you’re ready to eat the frozen oatmeal, just pull it out the night before to thaw in the refrigerator. This should work whether you’re thawing a full pan or just an individual serving.

In the morning, bake the oatmeal in the oven as directed in the baked oatmeal recipe above if you haven’t baked it yet, or reheat it in the microwave for 1 to 2 minutes (depending on your microwave’s power level and your preferred level of heat) and enjoy!

This Freezer-Friendly Baked Oatmeal recipe is a great healthy breakfast option or dinner meal for those who live a busy lifestyle. While it does require some prep time, making one or two batches allows you to have a healthy breakfast at your fingertips.

Your Baked Oatmeal Questions, Answered

Readers have asked some great questions about baked oatmeal, and we’ve answered the most common ones here. If you’re wondering about something else, ask in the comments and join the conversation.

How Long Does Baked Oatmeal Last?

Baked oatmeal lasts about 4-5 days when stored in the fridge. To maximize freshness, store baked oatmeal in an airtight container. If you need to store it longer, consider freezing it.

Can baked oatmeal be frozen?

Yes, baked oatmeal freezes well, making it an excellent option for meal prepping your breakfast. Ensure it is properly wrapped and stored to maintain its quality and taste.

How Long Does Cooked Oatmeal Last in the Fridge?

Cooked oatmeal lasts 4-6 days in the fridge when stored in an airtight container. Of course, I don’t always eat it that fast, so I might have a few days’ worth of baked oatmeal in the fridge and put the rest in my meal prep containers to freeze for later.

How to Reheat Cooked Oatmeal?

To reheat cooked oatmeal, place the desired amount in a microwave-safe bowl. Add a splash of water or milk to restore its creamy texture. Microwave on high for 1-2 minutes, stirring halfway through.

Alternatively, reheat it on the stovetop over low heat, adding liquid as needed. Just be sure to watch it carefully so it doesn’t splatter.

Tell Us How You Made It!

Did you try this recipe, or do you have a favorite variation you always come back to? Share your experience in the comments, what you loved, what you tweaked, or how it worked for your routine. Your tip might be exactly what another reader needs.