Loaded with walnuts, this keto banana nut bread bakes up spongy and moist, just 2.2g net carbs per slice. My trick is banana extract instead of real bananas.
I’ve been making this keto banana nut bread for years, and it’s one of those recipes I keep coming back to. The whole trick is banana extract instead of real bananas, which gives you all that warm banana flavor without the carbs. I use the same kind of flavor-swap approach in my keto pumpkin bread and chocolate zucchini muffins, where one ingredient change makes the whole recipe work.
The base is almond flour with a couple scoops of protein powder, and that combination is what makes the texture right. Almond flour on its own can be dense and crumbly, but the protein powder creates a matrix that traps air bubbles from the baking powder. The result is bread that’s actually spongy, not just “keto spongy.” I’ve tested this side by side with coconut flour as a protein powder substitute, and while coconut flour works in a pinch, the protein powder version has better structure and a more natural crumb.
A note on the butter: I originally developed this with 2.5 sticks, and I’ve heard from several readers that it felt greasy. I went back and tested it with closer to 1.5 sticks and the bread still holds together, stays moist and has plenty of richness. If you’re sensitive to butter-heavy bakes, start with 1.5 sticks and see how you like it. The sour cream in the batter provides enough fat and moisture to compensate. You can also swap in full-fat Greek yogurt or heavy cream if you prefer.
I eat slices of this with my morning coffee or warmed up as an afternoon snack. It pairs well with a smear of cream cheese or a drizzle of butter. If you’re looking for other breakfast bakes, my lemon poppyseed muffins and almond flour pancakes are in the same weekly rotation at my house.
Each slice comes in at 2.2 net carbs per slice, which means I can have a thick slice without thinking twice about it. The walnut topping gives it a crunch that makes it feel indulgent, and the cinnamon rounds out the banana flavor in a way that reminds me of the banana bread I grew up eating. This is the low carb version I actually want to make.
How I get real banana flavor without bananas
There are no bananas in this bread. Bananas pack about 27g of carbs each, so they’re not an option for low carb baking. But I figured out years ago (when I was developing my sugar-free banana pudding) that banana extract delivers the same warm, sweet flavor without any of the carb load.
I use about one tablespoon of banana extract, which is what I recommend starting with. If you want a stronger banana punch, go up to 1.5 tablespoons. I’ve also used concentrated flavor drops by Oooflavors, which are more concentrated so you only need 2-3 dropperfuls. Either option works, but I reach for the standard extract most of the time because I always have it on hand.
Chocolate chip banana bread
I add sugar-free chocolate chips to about half the batches I make. The chocolate and banana combination is hard to beat, and it makes this bread feel more like dessert. My favorite chips are from ChocZero because they’re sweetened with monk fruit instead of sugar alcohols, so no weird cooling aftertaste. I fold about 1/3 cup into the batter right before pouring it into the pans.
Which loaf pan to use
I use two 3 x 6 inch small loaf pans for this recipe. The smaller pans give you a better crust-to-crumb ratio, and the bread bakes more evenly at 325 degrees. But I’ve also made this in a standard 9×5 loaf pan when I didn’t want to split the batter. If you use a larger pan, add 20-25 minutes to the bake time and check the center with a toothpick. A cake pan works too. I’ve done it in an 8-inch round when I was out of loaf pans, and it baked up fine as a banana cake. If you enjoy almond flour baking, my gluten-free monkey bread uses a similar base.
How to store and freeze this bread
I keep this bread in the refrigerator for up to 5 days, loosely wrapped or in an airtight container. It actually tastes better cold the next day once the flavors settle.
For longer storage, I wrap individual slices in plastic wrap, then store them in a freezer bag for up to 2 months. To thaw, I leave a slice at room temperature for about 30 minutes, or microwave it for 15-20 seconds. I warm mine in a toaster oven sometimes, which brings back that fresh-baked crispness on the edges. If you’re prepping breakfasts for the week, pair a slice with keto french toast for some variety.
How to make keto banana bread
Mix dry ingredients: almond flour, protein powder (or coconut flour), baking powder, cinnamon and salt. I always sift these together. Almond flour clumps badly if you skip this step, and those clumps show up as dry pockets in the finished bread.
Cream the butter and sweetener. This needs a few minutes of mixing until the color lightens and the texture gets fluffy. I use monk fruit sweetener.
Mix in wet ingredients: eggs one at a time, banana extract and sour cream. Adding eggs individually helps them incorporate fully.
Combine wet and dry. Fold in chopped walnuts or sugar-free chocolate chips if you want them mixed throughout.
Fill loaf pans lined with parchment paper and bake at 325 degrees for 30-35 minutes.
Key ingredients
Almond flour: The primary flour. It behaves similarly to all-purpose but needs help with structure, which is where protein powder comes in. I use the same almond flour base in my pecan pie muffins.
Protein powder: Creates a protein matrix that traps air bubbles and keeps the bread spongy. I use unflavored whey, but vanilla works too.
Butter: Provides moisture and flavor. I've tested this with 2.5 sticks and 1.5 sticks. Both work, but if you prefer less richness, go with 1.5.
Eggs: Four eggs strengthen the protein matrix that traps air from the baking powder, helping the bread rise.
Banana extract: The whole trick. Instead of ripe mashed bananas (27g carbs per banana), I add a tablespoon of extract for all the flavor and none of the sugar.
Sour cream: I add this for moisture and a slight tang that balances the sweetness. Protein powders and sugar-free sweeteners can dry out baked goods, and the sour cream fixes that. You can swap in full-fat Greek yogurt or heavy cream.
Preheat oven to 325 degrees. Spray two 3×6 inch loaf pans with cooking oil or line with parchment paper.
2
Get a small bowl
In a small bowl, sift together almond flour, protein powder or coconut flour, baking powder, cinnamon and salt. Set aside.
3
Cream the butter
In a large bowl, cream butter until light and fluffy. Add monk fruit and mix together for several minutes until light in color and fluffy. Reserve ¼ cup of butter mixture for later.
4
Add the eggs
Mix in eggs one at a time, stirring in between until combined. Add in banana extract and sour cream. Mix until combined.
5
Add dry ingredients
Slowly add dry ingredients while mixing continuously.
6
Add the walnuts
Add ¼ cup chopped walnuts. Mix until fully combined.
7
Place the batter
Spoon batter into the loaf pans filling with batter to almost the top of the loaf pan (about 1/2 inch from the top) The batter won’t rise a whole lot.
8
Top with butter
Combine reserved butter with remaining 1/4 cup of chopped walnuts and spoon over the top of each loaf.
9
Bake it
Bake at 325 degrees for 30-35 minutes or until set. Remove from the oven and let cool before serving.
Nutrition
Per serving: 1 slice
Calories
302
Fat
28.4g
Protein
9.5g
Total carbs
3.8g
Net carbs
2.2g
Nutrition is an estimate calculated from the ingredients listed. Brands vary, so check labels if you track closely.
Frequently Asked Questions
Are bananas keto?
I get asked this a lot. One medium banana has about 27g total carbs and 14.5g sugar, so no, bananas aren't keto friendly. Even half a banana would eat up most of my daily carb allowance. That's exactly why I developed this recipe with banana extract instead. You get the flavor of ripe banana without the carb load.
Why does my banana bread feel greasy when I slice it?
Let the bread cool completely before slicing. Cutting into it warm makes the melted butter run, which makes the crumb feel greasier than it actually is. Once it has fully cooled, the texture firms up and slices cleanly. If it still feels too rich for you after cooling, I cover reducing the butter in the post above.
Can I use a regular-sized loaf pan instead of mini pans?
I use two 3x6 inch mini pans, but I've also baked this in a standard 9x5 loaf pan. The key difference is baking time: plan on 55-60 minutes instead of 30-35. Check the center with a toothpick. If it comes out clean, you're good. A reader who tried a 9x5 found the center needed extra time, so don't pull it at the mini-pan mark.
How do I prevent the top from getting too brown?
My go-to move is tenting the pan loosely with foil after 20 minutes. The almond flour surface browns quickly at 325 degrees, and the walnut-butter topping speeds that up even more. I lay a sheet of foil over the top without sealing it and let the bread finish baking underneath. This keeps the top golden instead of dark.
Can I make this dairy free?
I've done a dairy-free version using coconut oil in place of butter (about 3/4 cup) and swapping the sour cream for unsweetened almond milk yogurt. The bread came out a little denser but still had good banana flavor. You lose some of that buttery richness, but the coconut oil adds its own subtle sweetness that I actually liked.
Hi Annie, I trust your baking recipes to actually work. Sixth loaf of this and I finally stopped using the protein powder, swapped in the coconut flour instead. Crumb came out a little tighter but it slices clean without falling apart, which is what I wanted for morning toast. Mine always needs closer to an hour at 325 than the time listed, so I just start checking early now.
Hey Annie, been making stuff off this site for months and it never lets me down! The banana extract idea is way easier than hunting down the right bananas. Mine came out moist and I got walnut in every slice!
I’m such a non-baker that I bought the little loaf pans specifically for this recipe, expecting to toss them after one failed attempt. It actually worked first try and I’m still not over it. Ate two slices before I even thought to check the carbs, and it’s only 2.2 grams. Had to look it up twice.
Banana extract worked better than I expected, and the ratio is spot on. One heads up: if you use a standard 9×5 pan instead of two small loafs, the center will be underbaked at the listed time. Mine needed 12 extra minutes, toothpick was the only way to tell.
That 12 extra minutes tracks with what I’ve seen. I mention it in the FAQ but it probably needs to be more visible in the recipe card itself. The 9×5 takes 55-60 minutes total, not the 30-35 the mini pans need. Toothpick is the only way to call it because almond flour browns fast and the top looks done long before the center is. Glad the extract ratio worked. I tested it somewhere around 6 or 7 times before 1 tablespoon felt right.
My grandmother made banana nut bread every Saturday morning, and going keto meant letting that go. One slice of this and I was back there, that warm kitchen smell, the walnuts in every bite. Didn’t realize how much I missed it.
The walnuts were important to get right. Half go into the batter, half pressed into the top so they toast up while it bakes. Glad it brought that back.
The texture is exactly right – moist without being gummy. My one thing: a full tablespoon of banana extract reads more banana candy than banana bread. I pulled it back to 2 teaspoons and it clicked into place. Four stars because that tweak made a real difference, but the base is genuinely SO good.
Brand matters a lot with banana extract. Some are way more concentrated. 2 teaspoons of the strong stuff hits the same as a tablespoon of a milder one.
Banana bread was the one thing I told myself I was just giving up when I started keto, so I made this half expecting to be sad about how different it was. It’s not different. The banana extract comes through really strong (almost more than the real thing, which I did not expect), and that crumb is exactly what I missed for the last year. Took off a star only because I can’t seem to make it fast enough to keep any in the house.
I’ve worked through probably six keto banana bread recipes at this point, most of which either taste like almond flour with a faint banana note or come out so dense they’re basically a brick. The sour cream here is what the others are missing. It gives the crumb that slightly tender pull you expect from real banana bread instead of that gummy, protein-powder chew. I go a touch heavier on the banana extract than the recipe calls for, but that’s just what tastes right to me.
My daughter walked in while this was cooling and immediately said ‘is that banana bread?’ (which, yes, it smells exactly like it). She’s 11 and very vocal about my keto experiments, so her eating two slices without a word said it all. The banana extract surprised me too, more convincing than I expected from one tablespoon. Four stars, but I’d bump the sweetener up next time.
Two slices from a kid who doesn’t hold back, that counts for a lot. On the sweetener, I’ve gone up to 3/4 cup before and the texture holds fine. Go for it.
Banana extract always makes me think of artificial flavoring, so I kept putting this off. Made it on a snow day and the crumb was spongy and moist in a way I wasn’t ready for. Nothing chemical about it.
Used coconut flour instead of protein powder since I didn’t have any and it still turned out SO good and moist. Beginner tip: soften the butter in 10-second microwave bursts, the batter comes together in like two minutes.
Made this today, used orange extract instead of banana – great flavor! I also added 1/4 cup finely chopped cranberries – trying to recreate my favorite orange cranberry bread. But I agree with the other commenters, very greasy. I think 1 – 1/2 cubes of butter would be enough, especially with all the fat from the egg yolks. Also I baked it in a regular sized loaf pan – turned out fine but had to increase baking to an hour to set in the middle.
Orange cranberry sounds great actually. And yeah on the butter, 1.5 sticks is enough. I went back and tested it after the feedback came in and the bread still holds.
I carefully measured all ingredients to make this and it was waaaaay too much butter and the bread almost crumbles apart very easily. Overall it was ok and decent as far as any type of “keto” bread goes but I’m very picky about banana bread.
You can always decrease the amount of butter. I’ve made it several times and it doesn’t crumble apart. You should let it cool completely before slicing into it.
Awesome banana bread, when l saw the above review l did less butter and it came out pretty good but l think next time l will use less again.
Overall best keto banana bread so far.
This was a simple recipe and cooked up very pretty. But it was waaaay to much butter for me. I almost got sick trying to eat a piece. I will definitely have to make adjustments should I make this again. Thanks for your efforts.
Yeah, 2.5 sticks is a lot. I’ve tested it down to 1.5 and the bread still holds together fine, still moist. That’s probably where I’d start if you try it again.
