This simple, one-bowl Keto Banana Bars dessert recipe with a creamy brown butter frosting is the moistest and dense blondie keto recipe. With the perfect balance of rich and decadent gooey gluten-free blondie topped with a sugar-free brown butter frosting, what more could you possibly want in a keto dessert?!! Plus, at only 3 g of carbs per square, you can have a little banana and still be in ketosis!

These blondies are like no other. One of the many reasons why I love them is because of their unparalleled texture. They’re sort of like fudge and sort of like a blondie. Smack dab in the middle of those two heavenly dessert categories.

The edges are chewy and the centers are soft. I love goodies with dense, sugary centers like my Easy Keto Cheesecake Cookie Dough Bars and my Keto Blueberry White Chocolate Chip Cookies And, the fact that there is even more heavenly sugary frosting on top of the blondies too... I think I have died and gone to heaven!

A blondie can never ever truly be too dense, moist, or sweet, can it?

I have reworked this recipe several times as it always seems like we have one lonely over-ripened banana by the end of the week. I have never been a huge banana fan but when it comes to Banana Bread or anything baked with banana, move out of my way!

Although this recipe calls for brown butter frosting, this recipe is so good without it that you can absolutely omit it...yes, I can't believe that I am telling you to leave it off by these bars are so good on their own, that you can either add it or save some time and omit the frosting.

Table of Contents

Keto Banana Bars Details

Texture: This is basically a super moist and dense blondie recipe. Do NOT expect light and fluffy when it comes to these bars! You’ll notice I used melted butter which helps to melt the brown sugar and allows this recipe to come together VERY quickly. All you need is 1 bowl and a spoon and you can make the batter in about 5 minutes. I recommend slicing these bars after they have FULLY cooled so that they are nice and dense and hold together well.
Flavour: If you love banana bread but don't want all the carbs, then this is the perfect recipe for you. I recommend that you use a banana that is fairly brown to ensure that you get the most "banana-y" flavour. You can leave these banana blondies plain but I certainly didn’t regret garnishing it with a glossy browned butter topping. Yes, these banana blondie bars are nearly perfect.
Ease: I have a basic butter-sugar-egg bar recipe on our hands and the great news is that there’s no crazy assembly or complicated decoration required. All of the equipment (bowl and a spoon) and ingredients are pretty standard for a baking recipe. We always appreciate an easy dessert that delivers big.
Time: Set aside only about 5-10 minutes of time to prep the batter and about 20 minutes for the bars to bake. Then, it is just a matter of patiently waiting until the banana bars have cooled and have been frosted.

easy keto snack recipe idea - Banana bread blondie bars

WHY MAKE BANANA BLONDIE BARS INSTEAD OF JUST MAKING BANANA BREAD?

There are so many reasons why banana bars are so much better than banana bread:

it is the perfect way to use up the lonely single banana that has gotten too rip (banana bread requires at least 3-4 over-ripe bananas)
it bakes in about 20 minutes (banana bread takes about 45-60 minutes)
it is significantly lower in carbs than banana bread
it is perfect to serve as a snack or to pack in your kids' lunch boxes

WHAT MAKES THESE KETO BLONDIES SO GREAT?

they are gluten-free and sugar-free
they only require a handful of ingredients
they take under 30 minutes to make from beginning to end
they are packed with collagen which is great for your hair, joints, and cartilage
they are the densest and delicious blondies EVER!

What are Collagen Peptides

Collagen peptides are small pieces of protein from animal collagen. Collagen peptides are used for aging skin and osteoarthritis. They are also used for osteoporosis, brittle nails, muscle strength, and many other conditions.

As far as using them for baking, Collagen Peptides add an extra level of "denseness" to baked goods. This is the opposite of using Whey Protein powder which actually causes baked goods to rise.

Banana Blondies INSPIRATION

These keto blondies are a combination of several of my favourite recipes.

By combining the base of my Keto Cranberry Cream Cheese Bars - Nut-Free along with the moist and delicious banana flavour like in my Healthy Moist Gluten-Free Instant Pot Banana Bread, these blondies were created!

delicious keto banana bread bars with sugar-free bown butter frosting

Sugar-Free Banana Bread Blondies Batter

If you are a beginner keto baker, I want you to feel confident when it’s your turn to try this gluten-free and sugar-free blondie recipe, so I am going to explain each ingredient. If you keep scrolling, you’ll find the full printable recipe.

Butter & Sweetener: Like many cake recipes, creamed butter & sweetener make up the base of this recipe. For this recipe, you don't have to worry about whether or not your butter is at room temperature as you are going to melt the butter in the microwave or on the stovetop. Not only does this mean that the sweetener will easily blend into the butter but it also means that no electric mixer is needed - just take a large spoon, spatula, or whisk and combine the two ingredients.
Egg: I am only using 1 egg in this recipe. Although eggs add structure and tenderness to these blondies, if you add too much egg, these blondies will end up more "cake-like" than the dense blondie texture we are looking for.
Vanilla Extract: Vanilla extract adds flavor. If you have homemade vanilla extract on hand, this banana bread blondie recipe is a great place to use it!
Almond flour, Flaxseed meal, and Collagen Peptides: If you don't have any collagen peptides, replace the collagen with almond flour and add an additional ⅛ teaspoon of xanthan gum
Baking Soda: Baking powder adds lift to baked goods so we are only going to add ¼ teaspoon so as to not make these bars too light and airy.
Salt: Salt offsets the sweetness.
Ripe Banana: Use a banana that is fairly brown on the outside for the most flavourful banana taste. If you feel like your banana is more on the ripe side, feel free to add some banana flavouring - you will only need about ⅛ tsp. Also, the banana helps to add moisture to the bars which help to keep them nice and dense, just like a blondie should be!

ARE BANANAS KETO-FRIENDLY?

Bananas are high in carbs. In a single small banana (about 4 oz peeled) there are about 17 g of carbs of which 2 grams are fibre grams.

So the net carbs of a small banana come in at about 15 g of carbs.

If you cut these bars into 16 squares, that means that the banana adds under 1 g of carbs per square.

When I put this recipe into My Fitness Pal, the banana blondies (without the frosting) comes in at only 51 calories, 2.5 g of fat and 2.3 g of total carbs and net carbs of 2 grams!

Add the sugar-free brown butter fosting and you should still be able to keep a slice of this cake at under 3-4 grams of carbs!

easy 1 bowl low carb gluten-free banana blondies

You’ll Love This Brown Butter Frosting

Feel free to serve these banana bread blondies plain, but if there’s an opportunity for eating delicious frosting, I say we should take it! Made with just 4 basic ingredients, it’s thick, glossy, and eventually sets into a fudge-like consistency.

Other options are Sugar-Free Cream Cheese Frosting, salted caramel, or serve each slice with fresh whipped cream.