May 27, 2016 5 Comments


Seeing how much y’all loved my Fudge “Keto” Protein Brownies, I knew I had to make another version with peanut butter! I wouldn’t classify these Peanut Butter Protein Brownies as “keto” brownies, but they’re still super low in carbs with only 4g total per serving (2g net carbs). If you’re not a peanut butter fan, feel free to use almond butter, cashew butter, sunflower seed butter… whatever your heart desires!

Protein substitutions

I used Quest Protein Powder in Chocolate Milkshake for these brownies. You can use whatever whey you like, but some work better than others. Whey blends (like Quest) combining whey isolate, casein, and milk protein work best for baking! Whey concentrate comes in close second. Whey isolates are the absolute worst for baking. They always make baked goods come out spongey or dry (unless you use very little).

You may be able to substitute a Paleo or vegan protein powder in this recipe, although I haven’t tested it. In my experience, you’ll probably need extra liquid to thin out the batter if using a plant-based protein powder 😉

Sweetener substitutions

To add sweetness without any calories or sugar, I used my favorite organic stevia blend that’s twice as sweet as sugar with no bitter aftertaste. If your stevia tastes bitter, it’s probably a low-quality brand! I generally avoid store brand stevia and stick to either Truvia or Pyure.

Feel free to substitute the stevia blend for twice as much (six tablespoons) baking stevia, granulated erythritol, monk fruit blend, or a granulated sugar like coconut sugar (not keto). If using stevia extract or drops, refer to the brand-specific conversion chart.

Other substitutions

To create that fudgey texture, I used no sugar added peanut butter and egg whites. You can also try almond butter, sunflower seed butter, or tahini.

The egg whites can also be substituted for two whole eggs or a vegan egg replacer if you’re allergic to eggs.

I used almond flour which gave a nice tender crumb, but you could substitute additional peanut butter or 100% pure canned pumpkin and reduce the egg whites by one-quarter cup. You just might need to bake it a little longer! Feel free to also replace the almond flour with two tablespoons of regular flour (or 1 tbsp. coconut flour).

Baking temperature

You’ll notice the baking temperature is much lower than normal (300 degrees F)… that’s because these babies should be barely baked and gooey throughout. I might have even undercooked mine, as they were a little too gooey (but still delicious!)

Here’s the recipe for these Low Carb Peanut Butter Protein Brownies – please leave a comment below if you try it 😉

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Low Carb Peanut Butter Protein Brownies

These Low Carb Peanut Butter Protein Brownies are keto-friendly with just a few ingredients. Fudgey, rich, and oozing with peanut butter!
Course Dessert
Prep Time 10 minutes
Cook Time 15 minutes
Servings 8 servings
Calories 127kcal


  • 1/2 cup (60g) chocolate whey blend protein powder I used Quest brand in Chocolate Milkshake
  • 1/4 cup almond flour*
  • 3 tbsp. calorie-free sweetener* I used one that's twice as sweet as sugar
  • 2 tbsp. unsweetened cocoa powder
  • 1/8 tsp. baking soda
  • 1/8 tsp. salt optional
  • 1/2 cup (4 large) egg whites*
  • 6 tbsp. no sugar added peanut butter* divided
  • 1/4 tsp. vanilla extract

*See blog post above for substitutions.


    • Preheat oven to 300 degrees F.
    • Whisk together dry ingredients (through salt) in a medium mixing bowl.
    • Add egg whites, 5 tbsp. nut butter, and extract, mixing until smooth and thick.
    • Lightly spray a 7″x5″ baking dish with cooking spray, and spread batter in dish using a spatula.
    • If desired, melt another tablespoon of peanut butter in the microwave for 20-30 seconds and swirl throughout batter before baking.
    • Bake for 10-15 minutes until the center no longer jiggles, but is still gooey. Brownies will set as they cool, so be very careful not to over-bake.
    • Slice into eight pieces and enjoy!
    • Store leftovers covered in the fridge (no preservatives).


    Calories (per serving, including optional ingredients): 127kcal, Fat: 7.7g, Sat fat: 1.3g, Carbs: 4g, Fiber: 2g, Sugar: 1g, Protein: 11g, Sodium: 119mg

    5 Responses

    Sarah Wilkins
    Sarah Wilkins

    August 09, 2022

    Hi Kaitlyn! Protein powder recipes require a moisturizer to stay moist – that’s what the peanut butter does here. You could try pumpkin or banana instead of the peanut butter with some powdered peanut butter instead of the almond flour for a lower fat version. Haven’t tested that – but that’s what I would try ;)

    Kaitlyn C
    Kaitlyn C

    August 09, 2022

    Ever used a Peanut Butter powder in this recipe? We use PBFit regularly. Thanks!


    July 19, 2022

    I used Shaklee Banana Protein powder & that was a great flavor addition. Ours was kind of thick but we ate with butter or whipped cream.

    Sarah Wilkins
    Sarah Wilkins

    July 06, 2022

    Hey Jazmine! I actually have a brownie recipe specifically for collagen that would be better: https://nutritionistmom.com/blogs/blog/collagen-protein-brownies. You can substitute peanut butter for the almond butter ;)


    July 06, 2022

    Can I sub chocolate collagen for the whey protein powder?

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