Chewy Brownies, No Sugar, No Flour, No Oil

If you’re craving something fudgy yet wholesome, you’ve gotta try these Chocolate Banana Oat Brownies with Peanut Butter Swirl. They’re basically sugar free brownies thanks to the monkfruit sweetener, and packed with good stuff like ripe bananas and cocoa, with that dreamy peanut butter swirl on top to make your taste buds sing. I first whipped these up on a lazy Sunday afternoon when I had some overripe bananas just sitting on the counter getting sad, and let me tell you — the result was so good that I immediately forgot about my typical “I-have-no-time-to-bake” excuses. Plus, they’re chewy, fudgy, and absolutely guilt-free which means you can totally snack on these without the “should-I-even?” guilt trip.

Detailed Ingredients with measures

2 medium very ripe bananas (3 oz each) 1½ cups old fashioned oats, ground 1 large egg 3 tablespoons unsweetened cocoa powder 3 tablespoons monkfruit sweetener 1 teaspoon vanilla extract ½ teaspoon baking powder ¼ teaspoon baking soda Pinch of salt 1 ounce chocolate chips For Peanut Butter Swirl 2 tablespoons PB2 powdered peanut butter 2 ounces sugar free syrup (use as needed for a thick sauce)

Prep Time

10 minutes (mostly just tossing things into the bowl and grinding the oats – I have a Nutribullet and it comes in handy!)

Cook Time, Total Time, Yield

Cook time: 20 minutes Total time: 30 minutes Yield: 9 chewy brownies Honestly, there was a moment when I thought I overmixed the batter because it looked a little thick and sticky, but it baked up beautifully. The bananas naturally sweeten everything and keep it moist, so no oil or sugar needed here. The peanut butter swirl is the star — mixing the PB2 powder with sugar-free syrup was a tiny kitchen experiment. Tried a couple spoonfuls of straight PB2 before deciding it needed that syrup to actually swirl well and not just clump awkwardly on top. If you don’t have sugar free syrup, messing with a little water or almond milk might work too, but I haven’t tried that yet. I used parchment paper in my 8×8 inch pan because greasing alone sometimes leaves brownies stuck, especially with oat flour mixtures. Pro tip: let them cool enough before slicing! I sliced mine too soon (patience is a virtue, huh?) and ended up with some crumbly edges, but the flavor was still spot on. These aren’t the perfect glossy brownies you get from a box, but they have this cozy, rustic feel that’s totally inviting—a real “homemade with love and slightly distracted kitchen” kind of treat. If you’re on the fence about trying sugar free or flourless, give these a whirl. They’re comfort in brownie form, packed with fiber, and that peanut butter swirl? Oh man, it’s like a little surprise on every bite. Just grab a mug of tea or coffee and dive in—trust me, you’ll want to make these again before the bananas brown too much next time!

Detailed Directions and Instructions

Okay, first things first—preheat your oven to 350°F (175°C). While that’s heating up, grease your 8×8 inch baking dish with a little butter. Yes, butter! It’s that cozy little touch that keeps the brownies from sticking. Then, grab a piece of parchment paper and line the dish. Trust me, that parchment is your best friend for easy clean-up and smooth brownie removal later on. Now, grab your ripe bananas. I mean really ripe—those spotty sweet little things that almost seem too mushy to eat. Peel ‘em and drop them into your mixing bowl. Mash them up with a fork until the goop looks smooth, but a few little lumps here and there are just fine—they add character! Next, crack in the egg and sprinkle in that monkfruit sweetener. Give it all a good stir until it’s one friendly mixture. Time to toss in the dry stuff, but first, make sure your oats are ground fine. I use a Nutribullet for this because it’s fast and makes the texture just right. Pour in the ground oats, the cocoa powder (the unsweetened kind—no cheating here), baking powder, baking soda, a tiny pinch of salt, and vanilla extract. Stir like you mean it. You’re aiming for a batter that’s thick and uniform—like the kind you’d want to dig into with a spoon. Chocolate chips next. You can fold them gently into the batter or just sprinkle them on top once it’s in the baking dish. Either way, chocolate > no chocolate. Simple math. Now comes the fun part: the peanut butter swirl. Mix the PB2 powdered peanut butter with sugar-free syrup in a small bowl until it becomes a thick, spreadable sauce. If your mixture feels too runny, add a little more PB2, and if it’s too thick, a tiny splash more syrup will do the trick. Dollop this over the brownie batter and grab a knife or toothpick to swirl it around, making pretty little patterns. Don’t stress about your artistic skills here—my first swirl looked like a toddler’s doodle and honestly? It tasted amazing. Pop your pan in the oven and bake for 20 minutes. The smell will probably make it hard to resist sneaking a taste before the brownies are fully cool, but patience, my friend. Once out, let the brownies cool for a bit, which helps them set up nicely so they cut clean without crumbling into a sad mess.

Notes

Ripeness of bananas is key here. If your bananas are not super ripe, you’ll miss out on that natural sweetness and moist fudginess that makes these brownies irresistible. So, wait it out or nudge your bananas along on the counter for a day or two. Grinding your oats finely is definitely worth the extra step. I tried once with just regular oats, and the texture felt too grainy—like trying to eat rocks. Not fun. If you don’t have sugar-free syrup on hand, honey or maple syrup can work, but remember it might change the sweetness and consistency of your swirl. Don’t be shy about the peanut butter swirl! The PB2 with syrup combo is less oily than regular peanut butter, which keeps these brownies less greasy. But if you want a more traditional ooey-gooey swirl, swap out for creamy peanut butter and thin it with a bit of warm water. These brownies hold up well stored in an airtight container at room temp for a couple of days. They’re great for grab-and-go snacks when you’re mid-chaos and need a little chocolate pick-me-up. And hey, if your first batch comes out a bit more cakey or a bit less rich, blame the altitude, the oven calibration, or your dog’s very judgmental stare while you bake. Better luck next time.

Cook techniques

Mashing bananas

Use a fork to mash your very ripe bananas right in the bowl. Don’t sweat perfect smoothness—it’s okay if there are a few lumps! Those little chunks add charm and texture to your batter and keep everything from being too dense.

Grinding oats

I use a Nutribullet or food processor to blitz the oats into a fine, flour-like powder. If you skip this step, the brownies will be more granola bar-like—still yummy, just chunkier. Grinding gives that fudgy, uniform texture we all crave in brownies.

Mixing dry & wet ingredients

Combine your mashed banana, egg, and monkfruit sweetener first. Then sprinkle in the dry ingredients evenly. Mix gently but thoroughly—over-mixing isn’t the enemy here, but keep the batter uniform to avoid any oat clumps lurking in there.

Swirling peanut butter

Making the peanut butter swirl is a fun little step. Combining PB2 with sugar-free syrup turns out a sauce that’s so silky. Dollop it on top, then swirl gently with a knife or toothpick. Don’t overdo the swirling or you’ll lose that pretty marbled effect!

Baking and cooling

The bake time is short and sweet—20 minutes at 350°F. Keep an eye toward the end and poke with a toothpick; it should come out mostly clean but maybe with a crumb or two. Letting it cool just a bit before slicing helps the brownies set up so you won’t squish that peanut butter swirl.

FAQ

Can I use regular peanut butter instead of PB2?

Sure thing! Just know you’ll want to thin it out with a tiny bit of water or sugar-free syrup since regular peanut butter is thicker and oilier. The swirl won’t be quite the same, but hey, peanut butter is peanut butter, right?

What if I don’t have monkfruit sweetener? Can I substitute?

Absolutely, you can swap in any granulated sweetener like erythritol or a little honey or maple syrup if you don’t mind a touch of sugar. It might slightly change the texture, but it will still bake up delicious and fudgy.

Can I make these gluten-free?

As long as your oats are certified gluten-free, you’re good to go! The recipe is naturally flourless, so it’s perfect for gluten-sensitive friends.

Why do my brownies sometimes come out dry?

Oh, this happens when the bananas aren’t ripe enough or the oven runs hotter than expected. Using really soft, spotty bananas adds moisture and sweetness. Also, don’t overbake—start checking at 18 minutes if your oven is temperamental.

Can I freeze these brownies?

Yep! Wrap them tightly in plastic wrap or put them in an airtight container before popping into the freezer. They thaw well at room temp, and the peanut butter swirl holds up nicely too.

Why is the peanut butter swirl not swirling well?

Sometimes the PB2 and syrup don’t combine smoothly if the syrup’s a bit too thin or too thick. Adjust the syrup by adding small amounts until you get a spreadable but not runny consistency. If too runny, drizzle instead of swirl.

Can I add nuts or other mix-ins?

Definitely! Chopped walnuts, pecans, or even some shredded coconut would be fantastic. Fold them in with the chocolate chips or sprinkle on top before swirling the peanut butter. Just watch the bake time if you add a lot of extras!

Do I have to line the pan with parchment paper?

It’s a game changer. Parchment paper makes lifting out the brownies a total breeze and keeps clean-up easier. Greasing alone can sometimes lead to stuck edges, and nobody wants brownie heartbreak.

Conclusion

Honestly, these Chocolate Banana Oat Brownies with Peanut Butter Swirl have become a little favorite in my kitchen chaos. The way those ripe bananas sneak in natural sweetness and moisture makes the brownies so fudgy without needing any extra sugar or oil—win-win! Plus, the peanut butter swirl? Game changer. I remember the first time I made them, I was a bit skeptical about using PB2 with sugar-free syrup for the swirl, but it blended so perfectly, adding that luscious, nutty vibe without weighing things down or making the brownies greasy. If you’re anything like me and juggling a million things, this recipe is forgiving enough if you overmix a bit or forget to grind the oats super fine (guilty sometimes) but still turns out delish. It’s like a cozy hug from the inside—snack time or dessert, these will totally satisfy without the guilt. And hey, if you get a little messy or eat a bit of batter by the spoonful (not that I’m encouraging that!), you’re just making the memory sweeter. So give these a go when you need that quick comfort food fix that won’t derail your day.

More recipes suggestions and combination

Chocolate Avocado Banana Brownies

Swap out cocoa powder for half mashed avocado and reduce the bananas to one—you get that lush, creamy texture with an extra health boost. Top it with a dollop of Greek yogurt and a drizzle of honey for a perfect tangy balance.

Peanut Butter Banana Oatmeal Cookies

Use the same mash-n-mix method but make smaller dollops on a baking sheet. Bake as cookies instead for a grab-and-go snack. Add some chopped nuts or shredded coconut if you’re feeling fancy.

Chocolate-Cherry Banana Oat Bars

Mix dried cherries or fresh frozen ones into the batter before baking and swirl in a little dark chocolate spread with your peanut butter sauce. These bars keep well for a few days and are superb with morning coffee.

Peanut Butter Banana Smoothie Bowl

If you want to switch things up and skip the baking, blend the ripe bananas with PB2, a bit of cocoa powder, oats, and monkfruit sweetener, then top with chopped nuts, seeds, and fresh berries—smoothie bowl vibes but all the same flavors you love.

Layered Chocolate Banana Parfait

Layer warm brownie crumbles with Greek yogurt, peanut butter drizzle, and sliced bananas in a glass. It’s a no-fuss dessert that feels indulgent but keeps all that wholesome goodness. Give some of these a whirl whenever you feel like playing around with those coziness-boosting flavors. Sometimes the best kitchen experiments come from the “oops” moments turned surprisingly good, right?

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