Peanut Butter Brownie Baked Oatmeal Recipe

There's something magical about the smell of Peanut Butter Brownie Baked Oatmeal rising in the oven—rich cocoa, warm oats, and that irresistible nuttiness all melding into one heavenly aroma. It's like dessert met breakfast and decided to be the best of both worlds.

This baked oatmeal was born during a chilly weekend when all I had were pantry staples and a serious craving for something cozy yet satisfying. Now, it’s become my go-to recipe for busy mornings, meal prep, or even a healthy-ish late-night snack. Let’s dive into the why, what, and how of this chocolatey peanut butter dream.

Why You'll Love This Peanut Butter Brownie Baked Oatmeal

You’re about to fall hard for this breakfast that eats like a brownie but fuels you like oatmeal. Whether you’re a peanut butter fanatic or just need something quick and wholesome to power your mornings, this recipe checks all the boxes.

First off, it’s ridiculously easy to make. Everything mixes together in one bowl, bakes in the oven, and turns out perfectly every single time. No stovetop stirring or fancy tools required.

This dish is also meal prep gold. Bake once, and you’ve got breakfast ready to reheat for the next 4–5 days. It saves time, reduces stress, and keeps you from reaching for a granola bar in desperation.

Plus, it’s made with everyday ingredients. Rolled oats, cocoa powder, peanut butter—these are items you likely already have at home. No special trips to the store needed.

And finally, it’s kid-approved and adult-craved. Sweet enough to feel indulgent, but packed with fiber and protein to keep everyone full and happy.

Next, let’s break down the ingredients that make this dish a pantry-friendly powerhouse.

Ingredients Notes

The beauty of this Peanut Butter Brownie Baked Oatmeal is how it transforms a few staple ingredients into something that tastes like dessert for breakfast.

Start with old-fashioned rolled oats, which are the backbone of the dish. They provide that hearty texture and bake up beautifully into a soft-yet-chewy base. Quick oats will make it too mushy, while steel-cut oats won’t cook properly in this recipe.

Natural peanut butter gives the oatmeal its rich, nutty flavor and a creamy consistency. I prefer using the kind with just peanuts and salt. If you're using a no-stir version with added oils and sugar, the final product may turn out sweeter and a little softer—but still delicious.

Unsweetened cocoa powder brings the brownie factor. It lends a deep chocolate flavor that pairs perfectly with the peanut butter. Dutch-processed cocoa will give you a darker color and more intense flavor, while natural cocoa adds a lighter, more familiar brownie taste.

For sweetness, I use pure maple syrup. It adds just the right amount of sweetness without overpowering the chocolate and peanut butter combo. Honey works as a substitute, though it will change the flavor slightly.

Lastly, milk (dairy or non-dairy) ties it all together. Almond, oat, or regular whole milk all work great. You’ll also need eggs to bind it and a touch of baking powder for fluff. No special equipment is needed—just a mixing bowl, a whisk, and an 8x8 baking dish.

How To Make This Peanut Butter Brownie Baked Oatmeal

This recipe is so simple, you’ll wonder why you haven’t been making it every week. Here’s how it comes together:

Begin by preheating your oven to 350°F (175°C). Lightly grease an 8x8-inch baking dish or line it with parchment paper. This ensures easy cleanup and prevents any sticking, especially if you’re planning to slice and store it for later.

In a large bowl, whisk together the eggs, milk, maple syrup, peanut butter, and vanilla extract until smooth. If your peanut butter is thick, warm it slightly in the microwave for easier mixing.

Next, stir in the rolled oats, cocoa powder, baking powder, and a pinch of salt. Mix until fully combined. At this point, your batter should look thick and chocolatey—like brownie batter with oats mixed in.

Pour the mixture into your prepared dish and smooth the top with a spatula. For an extra indulgent touch, swirl a tablespoon of peanut butter over the top or sprinkle on some mini chocolate chips or chopped peanuts.

Bake for 30–35 minutes or until the center is set and the edges begin to pull slightly from the sides. A toothpick should come out mostly clean (some fudgy bits are okay!).

Let it cool for at least 10 minutes before slicing. This allows the oatmeal to firm up and makes it easier to cut into neat squares. From start to finish, you’re looking at about 45 minutes—including prep and bake time.

Storage Options

One of the best parts of baked oatmeal? It stores like a dream. Whether you’re meal-prepping for the week or saving leftovers, it’s incredibly fridge- and freezer-friendly.

Once completely cooled, slice the oatmeal into squares and transfer them to an airtight container. Refrigerated, they’ll stay fresh for up to 5 days. Keep a layer of parchment between layers if stacking to avoid sticking.

To freeze, wrap individual slices in plastic wrap and place them in a freezer-safe bag. They’ll keep well for up to 3 months. Just thaw overnight in the fridge or use your microwave’s defrost setting.

Reheating is simple: pop a slice into the microwave for 30–45 seconds. Add a splash of milk before reheating to keep it moist and give it that just-baked texture.

Variations and Substitutions

This recipe is endlessly customizable, so feel free to tweak it based on what you have—or crave.

Looking for a vegan version? Swap the eggs for flax eggs (1 tablespoon ground flax + 3 tablespoons water per egg) and use plant-based milk. Make sure your chocolate chips, if adding, are dairy-free too.

If you're not a fan of peanut butter, try almond butter or sunflower seed butter. Both work well and offer a slightly different nutty twist while keeping that rich texture.

Want even more protein? Stir in a scoop of protein powder or add chopped nuts or seeds to the mix. You could even swirl in some Greek yogurt on top before baking.

Craving dessert vibes? Toss in chocolate chips, chunks of banana, or a swirl of Nutella. It's a fun way to transform it into a brunch treat or post-dinner snack.

And if you're cutting back on sugar, reduce the maple syrup and add a mashed ripe banana for natural sweetness. The banana complements the peanut butter and chocolate beautifully.

The possibilities really are endless. Don’t be afraid to make it your own—baking is part science, part play, and all flavor.

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