Why spend money on expensive energy bars when you can make this easy low carb protein bar recipe with only 5 simple ingredients! These sugar free protein bars are chewy and fudgy yet they stay firm at room temperature.
Protein bars boost your energy after a workout and they're a fat-fuelled, protein-rich snack if you need a pick-me-up in between meals.
The main ingredient of this gluten-free, keto protein bar recipe is peanut butter. Peanut butter already has a high protein content, which I'm boosting with additional protein powder.
I experimented quite a bit with this recipe, because originally I wanted to create a no-bake protein bar. However, no mix was sufficiently firm at room temperature whilst still fudgy and chewy. I did not want to coat the whole bar in chocolate only to get around that issue.
The solution? 25 minutes in the oven. Yes, a little bit of baking produces delicious sugar free protein bars that you can carry around all day in your handbag until hunger strikes!
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Ingredients
Here are the ingredients you'll need:
- Peanut Butter - Must be soft and easy to scoop. Give it a good stir if necessary - especially in larger pots it tends to settle on the bottom of the jar and becomes hard. Also, check the label when buying peanut butter to make sure it does not contain added sugar! I like to use the Meridian brand - it contains 100% peanuts and nothing else.
- Protein Powder - I used unflavoured whey protein powder by Pulsin.
- Coconut Flour - to thicken and bind the bars.
- Granulated Sweetener - The sugar substitute you can see in the image above is golden Lakanto, which is an erythritol monk fruit sweetener blend. It is a brown sugar replacement. Xylitol or allulose will also work.
- Cocoa Powder - Unsweetened, for the chocolate layer.
See the recipe card for full information on ingredients and quantities.
Instructions
It's really simple to make this recipe! My homemade sugar free protein bars have a peanut butter layer and a peanut butter chocolate layer.
Scroll down to the recipe card for ingredient amounts, the detailed method and nutrition information.
STEP 1
Put the ingredients for the base and the top layer in separate bowls.
STEP 2
Mix the ingredients with a fork and knead with your hands until you have a smooth dough.
STEP 3
Line an oven-safe container with parchment paper. The mixture fills a space of 5 x 6 inches. Fill in first the peanut layer, then the chocolate peanut layer.
STEP 4
Bake the bars in the preheated oven on the middle shelf. They are done when the top does not glisten any more and has set while the edges are beginning to brown.
Then, let the low carb protein bars cool fully before you cut them. They will be fragile and soft while hot, but firm up as they cool.
Chef Katrin's Tips
#1 The peanut butter must be soft! Always stir it in the pot before you use it. Over time, peanut butter separates naturally.
#2 You can use crunchy or smooth peanut butter in this recipe. The bars with crunchy peanut butter can crumble a little when you cut them. For razor-sharp edges, I recommend using smooth peanut butter.
#3 Your dish is larger than 5x6 inches? No problem. Simply fold a bit of aluminium paper and use it as a separator. That way, you can use only part of your casserole dish. The mixture does not spread.
Variations
Almond flour - It's possible to use almond flour in place of the coconut flour. You may need to use 3 tablespoons of almond flour because it is less absorbent than coconut flour.
Dairy-free protein bars - Replace the whey protein with pea protein powder or another dairy-free protein powder. Note that I have not tried this yet - but it should work just as well.
Add flavor - Add 1 teaspoon of cinnamon for a taste variation or a pinch of sea salt.
More Chocolate - Stir a handful of sugar free chocolate chips into the mixture. Or, drizzle melted chocolate over the bars after they have cooled down.
Recipe FAQs
I do not recommend it. This would make the bars dry and brittle.
Yes, the recipe works with vanilla protein powder or chocolate protein powder.
The main reason why peanut butter protein bars turn out dry is that the peanut butter used was too firm. Always stir it before using to ensure it contains plenty of oil. Also, choose a natural peanut butter without additives such as palm oil. Another reason could be that the bars were flatter and therefore require less time in the oven.
Shop-bought low carb protein bars are convenient, but they are expensive. Plus, many contain additives to extend shelf life, questionable sweeteners and inflammatory vegetable oils. I've never sampled one that actually tastes good.
Storage
The bars keep on the kitchen counter for a couple of days and a good 7 days in the fridge.
You can also freeze them for up to 3 months.
More Low Carb Bars
- Keto Peanut Butter Bars2 Hours 15 Minutes
- Easy Keto Granola Bars30 Minutes
- Keto Twix Bars (Sugar Free)45 Minutes
- Keto Snickers Bars55 Minutes
More Keto Peanut Butter Recipes
- Low Carb Keto Peanut Butter Cookies15 Minutes
- Keto Peanut Butter Cheesecake4 Hours 15 Minutes
- Sugar Free Peanut Brittle (Keto)22 Minutes
- Keto Peanut Butter Mug Cake4 Minutes
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Recipe
Low Carb Protein Bars Recipe (Peanut Butter)
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary.
Ingredients
Base Layer
- ½ cup / 130g peanut butter unsweetened, soft
- 1 ½ tablespoon coconut flour
- 1 tablespoon protein powder
- 1 ½ tablespoon granulated sweetener
Top Layer
- ½ cup / 130g peanut butter soft
- 1 tablespoon cocoa powder unsweetened
- 1 ½ tablespoon granulated sweetener
- 1 tablespoon protein powder
- 1 ½ tbsp coconut flour
Instructions
- Preheat the oven to 175 Celsius / 350 Fahrenheit.
- Put the ingredients for the base and the top layer in separate bowls and mix with a fork, then knead with your hands to combine.
- Line an ovenproof dish with parchment paper. Spread the base layer, then add the top layer to fit a space of approximately 5 x 6 inches.Â
- Bake for up to 25 minutes. The bars are ready when the top has set and is beginning to brown around the edges. Remove and let cool to room temperature before cutting.
Notes
Nutrition
First published in March 2019. Republished with more information and tips in February 2024.
CK
i've made these and they are tasty but very very flat - they do not look like the picture at all! And there wasn't really enough for 8 large slices as appear in your images. Did I do something wrong?!
Katrin
Hi Chrissy, if you use the amounts stated in the recipe you should end up with the same amount of bars I did. It's a lot of peanut butter we're using! However, if you're using peanut butter that's quite liquid it's possible that it spreads out more. Is this what you're referring to?
Pam
I made these protein bar s and they came out perfect and look like the picture you have. I love the taste too
Katrin
I’m so glad you liked them!
Debbie
Mine were very tasty but so dry you could hardly get them down. There was no need to knead. The mixture was pretty soft. Did I do something wrong?
Katrin Nürnberger
It's possible that they were in the oven a little too long. If the mix was nice and soft, that's the most likely reason.
Rebecca :)
Hi, I've just made these but the mixture never 'glistened' to start with, so quite hard to tell when they had been baked enough! They're also quite dry. I substituted agave syrup for the sweetener (just did like for like, so 1.5 tbsp agave syrup instead of the brown sugar substitute) so if anything I'd have thought it should have been wetter pre-bake and gooier post-bake? I used Whole Earth organic crunch peanut butter, and the protein powder was a flavoured one from MyProtein. Would be very grateful for any tips on where you think I went wrong with consistency? Thank you 🙂 They taste great, just dry!
Katrin
Hi Rebecca, so sorry you had problems with the recipe! I think it's probably down to the consistency of your peanut butter. I always have a litre pot of Meridian peanut butter. The oil tends to collect on top, so if you don't stir it up properly, you'll end up with really hard and crusty peanut butter at the bottom. If your peanut butter is hard to start with, you need to adapt the recipe and use less dry ingredients. I hope this helps and you will give it another go one day 🙂
Rebecca
HI Katrin, thanks v much for your reply. I bought the Meridian smooth peanut butter today and it's SO much wetter/more oily than the Whole Earth pb so Round 2 should be the right consistency - thanks for the advice. 🙂
Katrin
you're welcome Rebecca!!
Munchie
Hi, I would like to try making the peanut butter bars but you use erythritol which doesn’t agree with me (IBS). Can you please suggest an alternative sweetener? Thank you!
Katrin
You can replace it with any sweetener that works for your condition.
Fiona
Hi,I want to try these out but I'm not sure which protein powder to use. I'm guessing unflavoured would mean I can use it in different recipes but does say chocolate work better here?
Katrin
Hi Fiona, I think unflavoured protein powder is more versatile. You can add it to smoothies and also to granola for an extra protein boost. If you like the bars extra chocolatey, just add more cocoa powder 🙂
Fiona
Thanks Katrin, so glad I found your site. I really struggle to find gluten free recipes that aren't hugely com pled but still taste of sadness. I can't wait to try these out ☺
Christy
I tried making these for the first time tonight and the flavour was fantastic but I found the consistency a little too soft (they were similar to the inside of a peanut butter cup). I did swap out the coconut flour for almond flour and increased it to 3tbsp. I also noticed my peanut butter seemed super liquidy so that may have been the cause. Any suggestions for how to make them a little more solid? Thanks!
Katrin Nürnberger
The rough conversion from coconut flour to almond flour is x3, so next time try using a little more. Also, the consistency of the peanut butter will have an impact - the more liquid it is, the more flour you'll need to make the bars firmer. I'm sure next time you'll get the to be just right 🙂
Jackie McDonald
Can I make these without the protein powder.
Katrin Nürnberger
You need to use something else then that thickens the bars. More coconut flour, or almond flour, powdered chia seeds, that kind of thing.
Maeve
Can you use coconut sugar instead of granulated erythritol? 🙂
Katrin
Yes, absolutely!
Megan
What can i substitute the coconut flour with, I'm allergic to any coconut products.
Thank you
Megan
Katrin
Hi Megan, I'd replace it with 3 tbsp almond flour.
Dawn
I am trying to work out how many pieces this makes to calculate the calories. Can you advise?
Katrin
I always calculate the nutrition per portion. I cut 8 pieces, so the calories are stated per protein bar/= 1 portion. They are filling, so you could also cut into 16 squares and halve your calories.
Desiree Currie
My daughters kindergarten is 'peanut free' - do you think this recipe would hold together as well with almond or cashew butter for example? If not I'll still make it - as an afternoon/home snack
Katrin
Yes, absolutely. Sometimes my almond butter is more liquid than peanut butter. If you cannot knead the "dough" without getting sticky hands, just add an extra 1/2 tbsp of coconut flour. Alternatively, you can also leave the mix in the oven for longer.
Colleen Schoneveld
to Desiree. If your child's school is "Peanut free" they actually mean "Tree nut free" as well.
The best substitute for peanut butter is Sunflower butter. Though it is expensive.
Ruth Gallagher
what can i substitute for the protein powder plz?
Katrin
Hi Ruth, I would try with either 1 tbsp almond flour OR an additional 1/2 tbsp coconut flour - but I haven't tried this myself. I think this recipe can handle all kinds of substitutions. All you want is to make sure your mix does not get too dry. The bars will still taste good, but they will become brittle and crumbly.
Ruth Gallagher
thanks so much, going to make these over the weekend
Scally Wag
Hi.... these look great! Can you use an extra tblsp if coconut flour instead of protein? Im not keen! Or is there anotjer alternative? Thanks!
Katrin
I would try 1 tbsp almond flour or 1/2 tbsp coconut flour instead of the protein powder. Coconut flour absorbs so much liquid, probably more than protein powder. You don't want your mix to get too dry. But that will also depend on how liquid your peanut butter is. It'll be a bit of trying out.
Elyse
Do you have to use whey protein or can you use a plant-based one? I have a plant-based protein powder that I would like to use instead of going out to but yet another powder.
Katrin
Of course, you can use any protein powder in this recipe.
Elyse
Perfect! Thx!