This easy recipe for homemade Monster Cookie Protein Bars is made with simple ingredients like natural peanut butter, protein powder, and oat flour. Perfect for meal prep, and can be frozen for later if needed!
One of my favorite things to do is find ways to make the things we normally buy at home. Not only does this save money, but it gives you completely control over the quality of ingredients.
My husband has been buying protein bars for several years now, as they are easy to grab and help him hit his protein goals for the day. I've tried most of the brands available in stores, but I always found them too dry and chalky.
These Monster Cookie Protein Bars are a homemade solution to packaged protein bars, and they taste SO much better than anything you would buy at the store.
Made with oat flour, protein powder, and maple syrup, these no bake bars are our new favorite grab-and-go snack.
Why You'll Love This Recipe:
- Easy to make. No special skills or equipment are needed to make these chewy monster cookie bars. Just mix everything together, press into a pan, and chill for an hour or so.
- Perfect for meal prep. Make a big batch of these early in the week and you'll have them on hand for a quick snack. They also freeze really well!
- A sweet treat. Just because you're trying to increase your protein, doesn't mean you don't want food that tastes delicious! This recipe has all of flavor of your favorite cookies, plus 15-20g of satisfying protein per serving.
- Simple ingredients. This recipe is naturally gluten-free and made with whole food ingredients like natural nut butter, maple syrup, and oats.
- Nut butter: I recommend using natural creamy peanut butter, as that's the most common flavor used in the classic monster cookie. If desired, you could use natural almond butter or cashew butter instead.
- Protein powder: I recommend using a good quality vanilla whey protein powder that you enjoy the taste of. You'll need 60 grams, which may vary in volume depending on the brand. For me, that was about ½ cup + 2 tablespoons.
- Oat flour: This can be purchased at the store, OR you could make your own in a blender or food processor. Use gluten-free oats if you need the recipe to be gluten-free.
- Maple syrup: Definitely make sure to use real maple syrup! If you can't find any, you could use agave instead (but honey is a bit too strong of a taste).
- Vanilla extract: All monster cookie recipes call for vanilla, so we'll be using here too for added flavor.
- Mini M&M's: These can be found in the candy aisle, or in the section with ice cream toppings. About ¼ cup is used for 6-8 bars.
- Mini chocolate chips: Adding a few mini semi-sweet chocolate chips to Monster cookie dough is a classic move. You'll need just 1 tablespoon for the whole batch.
- Small baking dish (or meal prep container): This is for pressing the dough into, which provides shape for your bars. I used a regular-sized meal prep containers, but a small baking pan or loaf pan would work well.
- Parchment paper: For lining your baking dish. It prevents sticking and makes removing the bars easy peasy.
Step one: Add the protein powder, oat flour, and nut butter to a medium-sized bowl (or the bowl of a stand mixer).
Step two: Pour in the maple syrup and vanilla extract.
Adding the M&M's
Step three: Use a silicone spatula to mix everything together until smooth and well combined.
Step four: Add in the mini M&M candies and mini chocolate chips and fold them in until well distributed.
Forming into Bars
Step five: Line a small baking dish or loaf pan with parchment paper (or wax paper) and add the Monster cookie dough into the middle.
Step six: Press the dough into an even layer and top with additional M&M's (if desired),
Cover and place in the freezer to chill for 1 hour.
Slicing into Bars
Step seven: After the chilling time is up carefully lift the bars out using the parchment paper and slice into 6 or 8 individual bars.
Wrap and place in an airtight container, and/or serve immediately.
Storing and Freezing
- After the bars have been sliced, wrap them tightly in plastic wrap and then place in an airtight container or a freezer bag.
- Keep in the refrigerator (tightly wrapped) for up to 1 week, or in the freezer for up to 2 months.
Top tip: If taking these Monster Cookie Protein Bars for a quick work snack, I like to toss them in the lunch bag frozen - they will be completely thawed by the afternoon!
- Protein powder. Some brands are more dense than others, so the best way to get an accurate measurement is to use a kitchen scale to weigh out 60 grams. That works out to ½ cup + 2 tablespoons for the brand that I use.
- Experiment. You don't have to make this recipe only in a bar form. They also work well to make scooped protein cookie dough, or protein balls.
- Mix well. If you want a smooth consistency, first mix together the dry ingredients, then add in the wet ingredients. Either way things mix together fairly easily, but separate additions makes it just that much easier to get chewy bars.
- Birthday Cake: Use cashew butter as your nut butter, and add ½ teaspoon of butter extract and ¼ teaspoon of almond extract. Stir in some sprinkles according to your liking, and top with additional sprinkles.
- Chocolate Chip Cookie Dough: Use cashew butter as your nut butter, and add ½ teaspoon of butter extract. Use ¼ cup of mini chocolate chips as your mix-in.
- Peanut Butter Oatmeal Cookie Bars: Make the recipe as is, but leave out the mini chocolate chips and mini M&M's. Leave 1-2 tablespoons of the oatmeal whole, and add chopped peanuts or Reese's pieces as your mix-ins.
It's not recommended to store homemade protein bars at room temperature. They often have a high moisture content and keep their texture better in the refrigerator or freezer, and spoil less quickly that way.
Yes, you can absolutely make your own oat flour if you don't have any on hand! Add quick oats or old-fashioned oats to a blender or food processor and pulse until it resembles a fine flour.
If you loved this recipe for Monster Cookie Protein Bars, let me know by leaving a 5-star review in the recipe card or comment below! You can also tag me on Instagram @dashfordinner.
Monster Cookie Protein Bars
- Small baking dish or meal prep container
- 1 cup creamy natural peanut butter *must be natural, the kind with oil separating out
- 5 tablespoons maple syrup
- 1 teaspoon vanilla extract
- ½ cup oat flour **see notes
- 60 grams vanilla whey protein powder about ½ cup + 2 tablespoons
- 1 tablespoon mini chocolate chips
- ¼ cup mini M&M’s
- Add the peanut butter, maple syrup, vanilla extract, oat flour, and protein powder to a large bowl.
- Mix everything together with an electric mixer – or by hand with a silicone spatula – until well combined.
- Add the mini chocolate chips and the mini M&M’s and fold them into the mixture until evenly distributed.
- Line a loaf pan or meal prep container with parchment paper and press the dough into the container. Use your hands or a spoon to firmly press it into the edges, forming a thick base.
- Cover the container or loaf pan with plastic wrap and place it in the freezer for 1 hour, or until firm.
- Lift the parchment paper out of the container and use a knife to cut it into 6-8 bars.
- Wrap the bars individually and store them in the fridge for up to 1 week, or placed in freezer bags and kept in the freezer for up to 2 months.
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