Peanut Butter Brownie Baked Oatmeal Recipe

There's something deeply comforting about the smell of peanut butter and rich chocolate baking together in the oven. This Peanut Butter Brownie Baked Oatmeal brings that same indulgent aroma into your kitchen, all wrapped up in a hearty, nourishing breakfast that tastes like dessert.

this Recipe

The first time I made this, it was on a lazy Sunday morning when I was craving something warm and satisfying but didn’t want the sugar crash that usually comes with brownies. This recipe hit the sweet spot—literally. It’s now my go-to when I want a feel-good start to the day that still feels a little decadent.

Let’s dive into what makes this baked oatmeal so special.

Why You'll Love This Peanut Butter Brownie Baked Oatmeal

Get ready to fall in love with your new breakfast obsession. This Peanut Butter Brownie Baked Oatmeal is the perfect balance between wholesome and indulgent.

First off, it's unbelievably easy to make. With just one bowl and a few pantry staples, you can mix this up in under 10 minutes. Then pop it in the oven and let the magic happen while you prep for your day (or sip your coffee in peace).

It’s also incredibly meal-prep friendly. Make a batch on Sunday and enjoy warm, chocolatey oats all week long. Just reheat and top with a drizzle of peanut butter or a splash of milk—breakfast, done.

If you’re watching your budget, this one’s for you too. It uses basic ingredients like oats, cocoa powder, and peanut butter—no pricey specialty items here. Yet the result tastes like something you’d get from a boutique bakery.

And let's not forget the versatility. Want it vegan? Use flax eggs and almond milk. Gluten-free? Choose certified gluten-free oats. This recipe welcomes your favorite substitutions with open arms.

Now that you know why this one’s worth a try, let’s look at what goes into it.

Ingredients Notes

The beauty of this recipe lies in its balance of wholesome and decadent ingredients. Each one brings something important to the table—whether it’s texture, flavor, or staying power.

Old-fashioned rolled oats form the heart of this baked oatmeal. They hold their shape beautifully during baking, giving the dish a chewy, satisfying texture. Avoid quick oats, which can turn mushy, or steel-cut oats, which won’t cook through in time.

Creamy peanut butter adds richness and healthy fats. It also enhances the brownie-like quality of the dish with its natural nuttiness. I like to use unsweetened peanut butter to control the sweetness, but any kind will do—just stir well if it’s the natural kind with oil separation.

Unsweetened cocoa powder delivers the deep chocolate flavor we associate with brownies. Use a good quality cocoa powder for the most intense, chocolatey bite. If you want to go ultra-decadent, you can even add a spoonful of Dutch-processed cocoa for a richer color and flavor.

Maple syrup sweetens the oatmeal naturally while adding a subtle depth that complements both the chocolate and peanut butter. If you’re out of maple syrup, honey or agave nectar are solid substitutes.

A few other kitchen staples round things out: baking powder for lift, vanilla extract for aroma, and non-dairy or regular milk to bind everything together. You’ll also need eggs (or flax eggs) to help the oatmeal set up like a brownie bar.

No special equipment needed here—just a mixing bowl, a whisk, and an 8x8 baking dish. If you have parchment paper on hand, lining your pan will make cleanup even easier.

How To Make This Peanut Butter Brownie Baked Oatmeal

Making this cozy breakfast is almost as easy as stirring up a batch of brownies—and just as satisfying.

Start by preheating your oven to 350°F. Grease an 8x8-inch baking dish or line it with parchment paper if you prefer an easy lift-out option. While the oven warms up, gather your ingredients and get your mixing bowl ready.

In a large bowl, whisk together your eggs (or flax eggs), milk, maple syrup, vanilla, and peanut butter. Make sure the peanut butter is fully incorporated—it might take a little extra whisking if it's thick. This wet mixture should look smooth and creamy.

Next, stir in the cocoa powder, baking powder, and salt until evenly combined. Then fold in the oats. The batter will be thick and slightly sticky—that's exactly what you want. If you're adding any extras like chocolate chips or chopped nuts, now’s the time to toss them in.

Pour the mixture into your prepared baking dish and smooth the top with a spatula. If you're feeling fancy, add a swirl of extra peanut butter or a sprinkle of chocolate chips on top. Bake for 30–35 minutes, or until the center is set and the edges pull slightly away from the pan.

Once out of the oven, let it cool for at least 10 minutes before slicing. This helps it firm up and makes it easier to cut into tidy squares. Serve warm or at room temperature, with a drizzle of milk or even a spoonful of yogurt for a protein boost.

From start to finish, you’re looking at about 45 minutes total time—with only 10 of those being active prep. Not bad for a breakfast that feels like dessert but fuels you like a champ.

Storage Options

One of the best things about baked oatmeal is how well it stores, making it perfect for busy weekdays.

You can store leftover portions in an airtight container in the refrigerator for up to 5 days. I like to cut it into individual servings so I can just grab and go in the mornings.

For longer storage, this baked oatmeal freezes beautifully. Wrap individual squares tightly in plastic wrap and place them in a zip-top freezer bag. They’ll keep well for up to 3 months. Just thaw overnight in the fridge or reheat directly from frozen.

To reheat, microwave a single serving for about 30–45 seconds, or until warmed through. Add a splash of milk to refresh the texture if it feels a bit dry. You can also reheat larger portions in a 300°F oven for about 10 minutes.

Variations and Substitutions

This recipe is endlessly adaptable, which makes it great for all kinds of dietary needs and preferences.

To make it vegan, substitute the eggs with flax eggs (1 tablespoon ground flaxseed + 3 tablespoons water per egg) and use plant-based milk. Make sure your chocolate chips, if using, are dairy-free.

If you're looking for a gluten-free version, all you need to do is ensure your oats are certified gluten-free. Everything else in the recipe is naturally gluten-free.

Want a lower sugar option? Reduce the maple syrup by half and add a mashed ripe banana for natural sweetness. It’ll also make the texture even more moist and cake-like.

Try different nut butters for fun variations. Almond butter gives a slightly sweet, mellow flavor, while sunflower seed butter makes this recipe nut-free and school-safe.

And if you're feeling extra indulgent, stir in some dark chocolate chunks or a spoonful of Nutella before baking. It’s your breakfast—you get to call the shots.

The beauty of this baked oatmeal is that it’s a canvas for your cravings. Once you make it a couple of times, don’t be afraid to mix things up. It’s hard to go wrong when you start with a base this delicious.

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