These healthy monster cookie bars are everything you love about monster cookies baked into bars and made healthier. They’ve got crisp, crunchy edges and an addictively chewy interior. And the best part—they’re 100% whole-grain, naturally sweetened and made with natural nut butter.

This healthy monster cookie bar recipe has been a true labor of love, and man do I love this recipe! I’ve tested and created many version of these bars—most of which were too thick and too cakey.

My goal was to create a cookie bar that was nearly identical to a classic monster cookie, and these are IT! Just like monster cookies, these bars have crisp edges and soft and chewy centers.

What I love most about these bars is that they’re made with wholesome, natural ingredients. The things we love around here! (Speaking of healthy desserts, check out these Healthy Chewy Chocolate Chip Tahini Cookies we can’t get enough of.)

oats, flour, coconut sugar, peanut butter, vanilla, cinnamon, candies, butter and an egg yolk measured out and set on a counter

Ingredients Needed

  • Unsalted butter, no need to soften it ahead of time, we’ll melt it before using.
  • White whole-wheat flour. If you’re curious to learn more about baking with whole-wheat flour, check out this article.
  • Old fashioned oats, do NOT use quick oats.
  • Kosher salt balances the sweetness of the bars. I do not recommend using table salt, though sea salt can be used instead. 
  • Baking powder
  • Ground cinnamon is optional but I find it adds just a bit of oomph to the bars. 
  • Coconut sugar is used instead of refined brown sugar in these monster cookie bars. It adds a toasty flavor and golden brown color. Look for coconut sugar in the baking aisle or in the health food section of your grocery store. You can also get it online.
  • Natural peanut butter that’s made with just peanuts and salt. It is SO important that you use natural peanut butter, NOT shelf stable peanut butter labeled as “natural.” Also, at room temperature the peanut butter should be fairly drippy.
  • Vanilla extract, I prefer to use pure vanilla extract.
  • Egg yolk from 1 large egg. Reserve the white for another use or your morning scramble.
  • Dark chocolate chips, I like Ghirardelli 60% cacao bittersweet chocolate chips or 72% cacao dark chocolate chips for these monster cookie bars.
  • Candy coated chocolate candies, I like the candies sold by Trader Joe’s that are naturally colored. Traditional m&m candies will also work.
  • Flaky sea salt is optional but adds a nice salty crunch to the monster cookie bars. 
cookie bars made with chocolate chips, oats and m&ms set on crumpled parchment paper

Our Favorite Brands of Natural Peanut Butter

FAQs & Test Kitchen Tips

The dough feels really stiff, is that correct?

The cookie dough in this recipe is quite stiff. The chocolate chips and candies might not stick in the dough very well, that’s OK! Do your best to mix the dough together, even getting your hands in there at the end if needed (I usually do!). 
Once the dough comes together, transfer it to the prepared pan. I recommend crumbling or separating the dough into large chunks and spreading it into an even layer before pressing it down. This will make it easier to spread it evenly into the corners. 
You can definitely use a stand mixer fitted with the paddle attachment if you’d prefer.

I have shelf stable natural peanut butter, does that work?

Unfortunately you’ll need natural peanut butter that’s made with just peanut and salt. The nut butter should be drippy at room temperature. I’ve listed my favorite brands above.

Can I use almond butter instead of peanut butter?

I haven’t tested this, but as long as you’re using natural almond butter made of only almonds and salt, it should work fine. 

I only have milk chocolate chips, is that OK? What about peanut butter chips?

You can use whatever chocolate chips you have on hand or prefer. I haven’t tested these with peanut butter chips, but it should work just fine.

Can I make these monster cookie bars gluten-free?

I do not recommend using a gluten-free flour blend in place of the whole wheat flour in this recipe.

Tip: measure everything out before you start.

Once the butter is melted and warm, it’s important to get a move on! Avoid letting the butter cool down before mixing in the other ingredients.

cookie bars made with chocolate chips, oats and m&ms stacked on top of eachother

More Healthy Desserts to Love…

Healthy Monster Cookie Bars

4.67 from 6 votes
Prep Time 15 minutes
Cook Time 15 minutes
Total Time 1 hour
Yield 9 bars
Category Dessert
Cuisine American
Author Lauren Grant


With nice crunchy edges and uber-chewy interior, these healthy monster cookie bars are pure bliss.


  • cup (75 grams) white whole-wheat flour
  • cup (57 grams) old fashioned rolled oats
  • ¾ teaspoon kosher salt
  • ¼ teaspoon baking powder
  • ¼ teaspoon cinnamon, optional
  • 5 tablespoons (70 grams) unsalted butter
  • 1 cup (147 grams) coconut sugar
  • 5 tablespoons (83 grams) natural creamy peanut butter* (¼ cup + 1 tablespoon)
  • 1 ¾ teaspoons pure vanilla extract
  • 2 large egg yolks (30 grams)
  • ¼ cup dark chocolate chips
  • ¼ cup candy coated chocolate candies such as m&m’s
  • Flaky sea salt, optional


  • Heat oven to 350ºF (176ºC) with rack set in middle position.
  • Grease an 8×8-inch metal baking pan with nonstick spray; line pan with 1 piece of parchment paper to form a sling.
  • In a medium bowl, whisk together flour, oats, salt, baking powder and cinnamon.
    oats and flour in a glass bowl
  • Cut butter into tablespoons and add to a large bowl. Microwave butter in 30 second increments until melted. 
  • Add coconut sugar, peanut butter and vanilla to warm melted butter and whisk until smooth; about 30 seconds.
    cookie dough in a bowl with egg yolk added
  • Add egg yolks and whisk until a smooth caramel-like batter is formed (this part can be annoying—the mixture will clump into a big shiny ball—this is what you're going for). Scrape whisk clean.
    caramel-like coconut sugar, peanut butter and butter mixture
  • Add flour mixture to peanut butter mixture and, using a stiff rubber spatula, mix until a dough comes together.
    cookie dough made with oats in a glass bowl
  • Roughly chop chocolate chips and chocolate candies; reserve 2 tablespoons for sprinkling over top.
  • Add remaining chocolate chips and chocolate candies to dough and mix to combine (you may need your hands for this bit since the dough is like a cookie batter).
  • Press dough into prepared pan in an even layer using hands.
  • Sprinkle reserved chocolate and candies over top and gently press into dough.
    cookie dough made with oats, chocolate chips and chocolate candies in a metal baking pan
  • Bake cookie bar until edges are lightly browned and center is puffed but set, 17–20 minutes. (Don’t over-bake!) 
  • Transfer pan to a wire rack and sprinkle bar with flaky sea salt, if using.
    cookie bars made with chocolate chips, oats and m&ms in a metal baking pan
  • Let bar cool in pan 10 minutes. Lift bar out of pan using parchment overhang and transfer to wire rack to cool completely. 
  • Using a large sharp knife, cut bar into 9 squares.


Peanut butter: it’s important to use natural peanut butter, the kind that’s only made with peanuts and salt. Check out the article above the recipe for a list of my favorite brands. I use salted peanut butter, but unsalted will also work.
5 tablespoons = ¼ cup + 1 tablespoon
I get the best results when I use the melted butter right away. Don’t let it cool down and re-solidify. 


Serving: 1 barCalories: 203kcalCarbohydrates: 25gProtein: 4gFat: 10gSaturated Fat: 5gCholesterol: 37mgSodium: 145mgFiber: 2gSugar: 16g
Like this? Leave a comment below!I love hearing from you and I want to hear how it went with this recipe! Leave a comment and rating below, then share on social media @zestfulkitchen and #zestfulkitchen!
cookie bars made with chocolate chips, oats and m&ms set on crumpled parchment paper

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About The Author

Lauren Grant is a professional culinary food scientist, food writer, recipe developer, and food photographer. Lauren is a previous magazine editor and test kitchen developer and has had work published in major national publications including Diabetic Living Magazine, Midwest Living Magazine, Cuisine at Home Magazine,,, and more.

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