Peanut Butter Protein Bars

By
Laurel Randolph
Photo of Laurel Randolph
Laurel Randolph
A fervid lover of the culinary arts and all things Instant Pot, Laurel has been writing about food for 10 years. One of her cookbooks was the #2 cookbook of 2017.
Learn about The Spruce Eats' Editorial Process
Updated on 07/9/21
peanut butter protein bars

The Spruce / Laurel Randolph
Prep: 15 mins
Cook: 0 mins
Chill: 60 mins
Total: 75 mins
Servings: 9 to 12 servings
Yield: 9 to 12 bars
Nutrition Facts (per serving)
305 Calories
22g Fat
19g Carbs
13g Protein
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Nutrition Facts
Servings: 9 to 12
Amount per serving
Calories 305
% Daily Value*
Total Fat 22g 28%
Saturated Fat 4g 21%
Cholesterol 1mg 0%
Sodium 145mg 6%
Total Carbohydrate 19g 7%
Dietary Fiber 4g 16%
Total Sugars 12g
Protein 13g
Vitamin C 0mg 0%
Calcium 57mg 4%
Iron 1mg 6%
Potassium 311mg 7%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

Protein bars are convenient for an on-the-go, filling snack. Whether you're on a workout regimen, vegetarian or vegan, or just want to get more protein, bars are an easy and delicious way to supplement your diet.

If you're buying protein bars at the store you might notice that they quickly add up. In addition, you don't have control over the often long list of ingredients, including various sweeteners and preservatives. Luckily, protein bars are easy to whip up at home. These peanut butter bars have a short list of ingredients and take just minutes to make. No stove or oven required!

Feel free to adjust the recipe to suit your tastes. Oat flour can be used instead of protein powder for a snack that is still protein-packed. The texture can change dramatically based on what protein powder you use—adjust as needed, adding more peanut butter or more powder, to get the right texture and avoid crumbly bars.

Ingredients

  • 1 1/2 cups creamy natural peanut butter

  • 1/4 cup honey

  • 1/2 cup unsweetened protein powder or oat flour

  • 1/4 cup flaxseed meal

  • 1 teaspoon vanilla extract

  • 1/2 teaspoon salt, optional if using unsalted peanut butter

  • 1/2 cup chocolate chips, about 3 ounces

  • 1/3 cup chopped roasted nuts, like peanuts, almonds, walnuts, cashews, or a mix

Steps to Make It

  1. Gather the ingredients. Line a loaf pan (about 8 1/2-x 4 1/2-inches) with parchment paper or greased aluminum foil, letting it slightly overhang on the sides.

  2. Add the peanut butter and honey to a heatproof bowl. Microwave in 20-second increments just until very smooth and easy to mix. Alternatively, you can soften the mixture on the stove using a double boiler.

  3. Add the protein powder or oat flour, flax, vanilla, and salt (if using) to the bowl with peanut butter and honey. Stir until well mixed.

  4. Pour the mixture into the prepared pan and press into an even layer.

  5. Add the chocolate chips to a heatproof bowl and microwave in 30-second increments (or use a double boiler), stirring, just until melted.

  6. Pour over of the peanut butter layer, making a thin, even chocolate layer on top. Sprinkle with the chopped nuts.

  7. Place in the fridge and chill until set, about an hour.

  8. Use the sides of the overhanging parchment to lift the set mixture out of the pan. Run a sharp knife under hot water, then slice into bars, running under hot water and cleaning off the knife every few slices to help make even cuts.

How to Store and Freeze

  • Store the bars in an airtight container in the fridge for a week.
  • To freeze, tightly wrap individual bars and place them in a zip-top freezer bag. Freeze for up to three months and defrost in the fridge before enjoying.

Tips

  • Natural, drippy peanut butter works best for this recipe and won't add unnecessary sugar and oil to the bars.
  • Include the salt if you're using unsalted peanut butter. Otherwise, leave it out or add to taste.
  • An unsweetened, plant-based protein powder works well, although any quality powder will work fine.
  • Different protein powders and peanut butters have different moisture levels, so you may have to adjust the recipe to get the right texture. It should be similar to peanut butter cookie dough—soft, not sticky or dry. If the mixture is too dry, add more peanut butter or even a little water a tablespoon at a time. If the mixture is too runny, add more flaxseed or protein powder.
  • To make oat flour, simply grind rolled oats into a fine powder using a blender or food processor. Make sure to measure after processing before adding to the recipe.

Recipe Variations

  • Swap the peanut butter for almond or cashew butter.
  • For extra sweetness, use vanilla or chocolate protein powder. Omit the vanilla extract.
  • For more chocolate, mix in 1/4 to 1/3 cup mini chocolate chips before pressing the peanut butter mixture into the pan.
  • Use dairy-free chocolate chips and protein powder for dairy-free protein bars.
  • Swap the honey for brown rice syrup.