Peanut Butter Brownie Baked Oatmeal

$3.77 recipe / $0.63 serving
by Beth - Budget Bytes
4.86 from 34 votes
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It’s been fooooorever since I’ve made baked oatmeal! I’ve been craving that peanut butter and chocolate lately, so instead of making a full blown dessert, I decided to work those flavors into a breakfast-worthy baked oatmeal. This Peanut Butter Brownie Baked Oatmeal is super rich and delicious without being overly sweet. In fact, it only has 1/4 cup brown sugar for the entire dish! The rest of the sweetness comes from mashed bananas, which also keep the baked oatmeal nice and moist. I like to keep my baked oatmeals with just a light kiss of sweetness, so if you’re looking for something more on the dessert level, consider doubling the sugar.

Want more oatmeal recipes? Check out our Oatmeal Recipe Archives!

A casserole dish with Peanut Butter Brownie Baked Oatmeal and a wooden spoon scooping a portion

What is Baked Oatmeal?

If you’re new to the baked oatmeal club, let me say first that the texture is not crunchy like granola (a common misconception when looking at the photos). It’s a moist semi-solid, similar to bread pudding. Baked oatmeal makes a great reheatable breakfast for the week and it even freezes great if you just want a portion once in a while. You can eat it cold, warmed up, or with a splash of milk over top. It’s totally up to you. It does need to be refrigerated after baking, though.

Remember how cocoa puffs would turn the milk in the bottom of your bowl into chocolate milk? This kinda does that. :D Hello childhood!

Can I Substitute the Banana?

While I haven’t tried any substitutes for the banana in this particular recipe, I do make other baked oatmeal recipes with applesauce or yogurt instead. My first choice here would probably be yogurt because the dairy will most likely pair well with the chocolate.

A bowl of Peanut Butter Brownie Baked Oatmeal with milk poured over top
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Peanut Butter Brownie Baked Oatmeal

4.86 from 34 votes
This Peanut Butter Brownie Baked Oatmeal is an indulgent-yet-healthy breakfast with rich chocolatey goodness and just a hint of sweetness.
This Peanut Butter Brownie Baked Oatmeal is an indulgent-yet-healthy breakfast with rich chocolatey goodness and just a hint of sweetness.
Servings 6
Prep 10 minutes
Cook 45 minutes
Total 55 minutes


  • 1.5 cups mashed ripe bananas (about 3 medium bananas) ($0.68)
  • 1 large egg ($0.27)
  • 1/4 cup natural peanut butter ($0.31)
  • 1/4 cup brown sugar ($0.04)
  • 1 tsp vanilla extract ($0.28)
  • 1/2 tsp salt ($0.02)
  • 1 tsp baking powder ($0.06)
  • 1/2 tsp cinnamon ($0.05)
  • 1/3 cup unsweetened cocoa powder ($0.29)
  • 2 cups whole milk ($1.12)
  • 3 cups old-fashioned rolled oats* ($0.50)
  • 2 Tbsp natural peanut butter (for topping) ($0.15)
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  • Preheat the oven to 375ºF.
  • Mash the bananas well, then place them in a large mixing bowl along with the egg, peanut butter, brown sugar, vanilla, salt, baking powder, cinnamon, and cocoa powder. Whisk until the mixture is mostly smooth (there may be small pieces of banana).
  • Add the milk to the chocolate banana mixture, and then whisk until smooth again. Add the dry rolled oats and then stir until combined.
  • Pour the oat mixture into a 2-3 quart casserole dish coated with non-stick spray. Drizzle the remaining 2 Tbsp peanut butter over the oats and drag a knife through to create swirls. If needed, warm the peanut butter slightly to make it runny enough to drizzle over the oats.
  • Bake the oats in the preheated oven for 45 minutes. Serve warm, or refrigerate until ready to eat. 

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*Do not substitute steel cut oats in this recipe and I suggest against using “quick” oats. Plain rolled oats will work, but will give slightly less texture than old-fashioned, which tend to be a bit chunkier.


Serving: 1ServingCalories: 384kcalCarbohydrates: 57.28gProtein: 13.25gFat: 14.3gSodium: 450.82mgFiber: 8.92g
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A wooden spoon scooping out Peanut Butter Brownie Baked Oatmeal from the casserole dish

How to Make Peanut Butter Brownie Baked Oatmeal – Step by Step Photos

Mashed Banana for Peanut Butter Brownie Baked Oatmeal

Begin by preheating the oven to 375ºF. Mash 3 to 4 bananas until you have 1.5 cups of banana mash.

First Ingredients for Peanut Butter Brownie Baked Oatmeal in a bowl

Place the mashed banana in a large mixing bowl along with 1 large egg, 1/4 cup natural peanut butter, 1/4 cup brown sugar, 1/3 cup unsweetened cocoa powder, 1 tsp vanilla extract, 1/2 tsp salt, 1 tsp baking powder, and 1/2 tsp cinnamon. Whisk these ingredients together until they’re fairly smooth.

Whisk Milk into Peanut Butter Brownie Baked Oatmeal batter

Add 2 cups whole milk to the mixture and whisk until smooth again. You may have some small chunks of banana and that’s okay.

Stir Oats into Peanut Butter Brownie Baked Oatmeal Batter

Finally, stir 3 cups old-fashioned rolled oats into the batter until everything is well combined.

Drizzle Peanut Butter Over unbaked Peanut Butter Brownie Oatmeal

Pour the oat mixture into a 2-3 quart casserole dish coated with non-stick spray. Drizzle 2 Tbsp more natural peanut butter over the oat mixture. You may need to warm the peanut butter to get it runny enough to drizzle.

Peanut Butter Brownie Baked Oatmeal ready to bake

I like to drizzle it in thin lines going horizontally, then drag a knife in the opposite direction a few times to create subtle swirls. Bake the oatmeal in the preheated oven for 45 minutes.

Baked Peanut Butter Brownie Baked Oatmeal

After 45 minutes the Peanut Butter Brownie Baked Oatmeal will look a little more like this and your house will smell AMAZING. Now you can dig in, or refrigerate it for later.

Peanut Butter Brownie Baked Oatmeal being served into a bowl from the casserole dish

Baked oatmeal is actually really good both warm AND cold.

Milk being poured onto a bowl of Peanut Butter Brownie Baked Oatmeal

But my favorite way to eat it is warmed with cold milk poured over top. :)

Close up of Peanut Butter Brownie Baked Oatmeal in the casserole dish
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    1. That will probably work fine, but it might end up tasking a bit more like dark chocolate rather than milk chocolate. :)

  1. I can’t comb through all 100+ comments but wanted to ask if you can skip the peanut butter since I detest peanut butter. I hope it does not affect the end result of the overall brownie. If so, is there a sub or should I change up the ratio of other ingredients if I omit the 1/4 cup natural peanut butter? (If you can revise in your original direction as a note that would be helpful). Thanks! :)

    1. Sure, you can just skip adding the peanut butter on top if you’d like. :) Since it’s just a topping, that won’t affect the oats themselves.

  2. Super delicious once again! I didn’t have whole milk so I used 1% and subbed a half a cup of yogurt in for richness. Would definitely make it again and I served it to friends who liked it too! With some vanilla greek yogurt it was like having a brownie sundae for breakfast! :P

    Going to try your other baked oatmeals soon!

  3. Hello! This sounds amazing, but I simply cannot stand bananas. What could I swap for bananas to make this? Thanks so much!

    1. In some of my baked oatmeal recipes I use applesauce or yogurt rather than bananas, but I haven’t tried either of them in this recipe to see how much it will alter the flavor and texture.

  4. An apotheosis of perfection!

    Absolutely stunned by how good this is—and how simple to make.

    Definitely going to be trying your other baked oatmeal dishes.  So perfect for meal prep and the cold weather that is coming.

    Thank you for sharing this.

  5. This is my first experience with baked oatmeal. The idea of heating it up and topping it with milk seemed odd to me, but I tried it. Wow! Absolutely love this and will make it many more times. Thank you so very much for the recipe and introducing me to a new and delightful breakfast option!!

    1. I always make these baked oatmeals with either oat or almond milk and they are always perfect!

  6. AMAZING! I used almond butter and it was so yummy. I didnt add the brown sugar, only used two bananas, and ended up using pb powder because I ran out of almond butter. Tastes like a brownie ah!

  7. I bought a big ass bag of quick rolled oats, can I use quick rolled oats for this and your other backed oatmeal recipes? Should the cooking time or liquid be adjusted?


    1. Quick oats have a lot less texture than old-fashioned rolled oats, so while you can use them you’ll end up with a mushier end product.

  8. This was my first go at a baked oatmeal, something I’m wholly unfamiliar with.

    I was looking for something to use some bananas I had received in a food box by mistake, so set I was to not waste food, and this was the recipe I chose. I preface this with the statement that I absolutely detest bananas and find their smell and taste noisome.

    I was surprised when this was done that the three whole bananas that I mashed up and put in this were undetectable, and the oatmeal was enjoyable. :)

  9. My boys are obsessed with pb&j, so I’m adapting this to make pb&j baked oatmeal! I doubled the PB and left out cocoa. Then I swirled PB and strawberry jam through the top before baking. I’ll come back to report how it turns out👍🏻

    1. It was delicious, and so pretty with the peanut butter and jam swirled on top…wish I could post a pic! I just left out the cocoa and doubled the peanut butter👍🏻