This Chocolate Banana Peanut Butter Baked Oatmeal is somewhere between breakfast oatmeal and a soft chocolate banana snack cake. Ripe bananas naturally sweeten the oats, cocoa gives every bite a rich chocolate flavor, and swirls of creamy peanut butter make the top extra satisfying.
It’s also an easy one-dish meal-prep breakfast. Bake a batch on Sunday, slice it into squares, and keep it in the refrigerator for quick breakfasts or snacks throughout the week. Leave off the peanut butter for a nut-free version when needed, and add chocolate chips when you want it a little more dessert-like.
Ingredients
For the Baked Oatmeal
- 1 cup (90g) old-fashioned rolled oats
- 1 cup (90g) oat flour*
- 2 large very ripe bananas, mashed
- ¼ cup (25g) unsweetened cocoa powder or cacao powder
- 1 teaspoon baking powder
- ¾ cup (180ml) milk or unsweetened plant milk
- 1 teaspoon pure vanilla extract
- ¼ teaspoon salt
- ¼ cup mini chocolate chips, optional
For the Topping
- ¼ cup creamy peanut butter
- 2–3 tablespoons chocolate chips, optional
*To make homemade oat flour, blend approximately 1 cup rolled oats in a high-speed blender or food processor until finely ground.
How to Make Chocolate Banana Peanut Butter Baked Oatmeal
Step 1 – Preheat the Oven
Preheat the oven to 350°F (180°C).
Lightly grease an 8x8-inch baking dish or line it with parchment paper.
The parchment overhang makes it especially easy to remove and slice the oatmeal for meal prep.
Step 2 – Mash the Bananas
Add the ripe bananas directly to the prepared baking dish.
Mash thoroughly with a fork until mostly smooth.
The riper the bananas, the sweeter and more flavorful your baked oatmeal will be.
Step 3 – Add the Milk
Pour in the milk and vanilla.
Stir until combined with the mashed banana.
Step 4 – Add the Dry Ingredients
Add:
- Rolled oats
- Oat flour
- Cocoa powder
- Baking powder
- Salt
Stir everything together until evenly combined.
Make sure there are no pockets of dry cocoa or oat flour hiding around the corners of the dish.
Step 5 – Add Chocolate Chips
If using chocolate chips, fold approximately ¼ cup into the mixture.
Spread the oatmeal mixture into an even layer.
Add the Peanut Butter Swirl
Drop small spoonfuls of peanut butter across the surface.
Use the tip of a butter knife to gently swirl the peanut butter through the chocolate mixture.
Don't completely mix it in—you want visible ribbons and pockets of peanut butter after baking.
Scatter additional chocolate chips over the top if desired.
Bake
Bake at 350°F (180°C) for 20–25 minutes.
The edges should look set and the center should no longer appear wet.
Insert a toothpick into the center. It should come out mostly clean or with a few moist crumbs.
For a softer, fudgier breakfast-bar texture, avoid overbaking.
Cool Before Slicing
Let the baked oatmeal cool in the pan for at least 15–20 minutes.
For clean meal-prep squares, allow it to cool completely before slicing.
Cut into 9 larger squares or 12 smaller snack portions.
Enjoy warm, room temperature, or chilled.
Chef's Tips for the Best Baked Oatmeal
- Use very ripe bananas. Heavily spotted bananas provide significantly more natural sweetness.
- Use old-fashioned rolled oats rather than quick oats for better texture.
- Homemade oat flour works perfectly here.
- Don't pack the cocoa powder when measuring.
- Add vanilla and a little salt to deepen the chocolate flavor.
- Use mini chocolate chips for more evenly distributed chocolate.
- Don't overbake. The center should remain soft and moist.
- Let it cool before cutting if you want neat bars.
- Natural peanut butter can work, but a thicker creamy peanut butter usually creates more visible swirls.
- Taste your bananas before deciding whether you need additional sweetness.
The Secret to a Moist, Fudgy Texture
The combination of mashed banana and oat flour is what makes this baked oatmeal feel much softer than a traditional bowl of oats.
The bananas provide moisture and natural sweetness, while oat flour absorbs some of that moisture and helps bind everything together.
Keeping some whole rolled oats gives the bars enough structure and chew that they still feel like breakfast rather than chocolate cake.
Most importantly, pull the pan from the oven once the center is set. Baking too long will make oat-based bars noticeably drier as they cool.
Want It Sweeter?
The original version relies heavily on ripe bananas for sweetness.
If your bananas aren't extremely ripe—or you're serving this as more of a dessert—you can add:
- 2 tablespoons maple syrup
- 2 tablespoons honey
- 2 tablespoons brown sugar
Chocolate chips also add sweetness without changing the consistency of the oatmeal very much.
Delicious Variations
Double Chocolate Banana
Increase the chocolate chips to ½ cup and scatter extra chips over the top.
Chocolate Banana Walnut
Skip the peanut butter and add ½ cup chopped walnuts.
Chocolate Almond Butter
Replace peanut butter with creamy almond butter.
Chocolate Strawberry
Fold ¾ cup chopped strawberries into the mixture and skip the peanut butter if desired.
Banana Bread Baked Oatmeal
Omit the cocoa and add 1 teaspoon cinnamon plus ½ cup chopped walnuts or pecans.
Chocolate Coconut
Add ⅓ cup shredded coconut and finish with a few chocolate chips.
Nut-Free Version
Simply omit the peanut butter or replace it with an appropriate nut-free seed butter.
Meal-Prep Tips
This recipe is particularly convenient for Sunday meal prep.
Bake and cool the oatmeal completely.
Slice it into individual portions and store them in an airtight container in the refrigerator.
In the morning, grab a square cold or microwave it briefly for a warm breakfast.
For a more substantial meal, serve it with:
- Greek yogurt
- Fresh berries
- Banana slices
- Milk
- Extra peanut butter
Storage
Refrigerator
Store in an airtight container for up to 4–5 days.
Place parchment between layers if stacking the squares.
Freezer
Wrap individual portions or separate them with parchment.
Freeze in an airtight container for up to 2 months.
Thaw overnight in the refrigerator or reheat directly from frozen.
How to Reheat
Microwave an individual square for approximately 20–30 seconds, adding more time as necessary.
For an especially good warm breakfast, add a small spoonful of peanut butter after reheating so it melts over the top.
Notes
- This recipe makes approximately 9 breakfast squares or 12 smaller snack portions.
- Regular cocoa powder and cacao powder both work, though their flavor and bitterness can differ slightly.
- Dairy or plant-based milk can be used.
- Chocolate chips are completely optional.
- The peanut butter can also be omitted for a simpler chocolate-banana version.
- Because most of the sweetness comes from fruit, very ripe bananas make a noticeable difference.
- For a more indulgent serving, warm one square and top it with banana slices, a drizzle of creamy peanut butter, and a few extra chocolate chips.