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Flourless Monster Cookie Bars (Gluten Free, Dairy Free)

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Flourless Monster Cookie Bars – These delicious peanut butter blondies are studded with rolled oats, chocolate chips, and chocolate candies. Plus, they’re gluten free and dairy free! The perfect easy treat to satisfy your sweet tooth.  

Overhead view of gluten-free flourless monster cookie bars

Do you ever get a recipe stuck in your head? For me, it’s kind of like getting a song stuck in my head. When that happens, I listen to it/sing it 9,000 times and then I get it out of my system. My latest cookie craving was kind of like that. I wanted monster cookie bars. Have I ever had monster cookie bars? Nope. Sure haven’t. But, I have had monster cookies and peanut butter blondies, and this seemed like the perfect marriage of the two.

Here were my criteria:

  • Soft, tender, and chewy on the inside, with some crispy, golden edges.
  • Plenty of oats, chocolate chips, and candies (classic for Monster Cookies!)
  • Easy recipe with simple ingredients
  • Gluten free & dairy free

We tried lots of combinations, but ultimately my favorite ended up being these flourless monster cookie bars. After SIX batches, we nailed the recipe, and my craving is totally satisfied. And, as a further benefit, now I’ve got the recipe the next time the craving strikes!

Let’s make these gluten-free monster cookie bars! (You won’t believe how simple and straightforward this ingredient list is!)

Square pan of Flourless Monster Cookie Blondies from One Lovely Life Flourless Monster Cookie Bars cut into squares

We took a classic monster cookie–peanut butter, oats, chocolate chips, and chocolate candies (like M&Ms) and gave it the gluten-free, dairy-free treatment. The end result was delicious monster cookie blondies made without flour!

  • NATURAL PEANUT BUTTER. You can go with creamy peanut butter or crunchy peanut butter, but we’re looking for JUST peanuts, or JUST peanuts and salt in the ingredients list. No oils, sugars, or stabilizers. Why? Because simple ingredients give you the drippy texture you need to mix into the batter and provide the right structure. Using peanut butter with oils or sugar won’t give you quite the same results. Target sells two good ones–this affordable organic one and this classic one. Sprouts and Trader Joe’s also carry some great options.
  • COCONUT SUGAR & PURE MAPLE SYRUP. It was a fun bonus that I could make these cookies naturally sweetened. I tried using all granulated sweetener or all liquid sweetener, but my favorite texture came from a combination. (If you don’t have/can’t find coconut sugar, you can sub brown sugar. Know they’ll be sweeter and the outside will crisp up just a bit more.)
  • EGGS OR FLAX EGGS. Pretty standard for cookies! The egg gives some puff and some softness to your monster cookie bars. If you don’t tolerate eggs or need a vegan option, you *can* use a flax egg or a powdered egg substitute (like this one or this one). The results are a little different, but passable if you need an egg-free option.
  • VANILLA, BAKING SODA & SALT. The usual suspects for a good, soft cookie. A generous splash of vanilla brings out the sweetness in all the other flavors and really pulls these together. Then baking soda gives us a little puff and softness, and salt balances out the flavor profile.
  • GLUTEN FREE ROLLED OATS. If you’re gluten intolerant, do be sure your oats are certified gluten free. Oats themselves don’t contain wheat gluten, but they’re often farmed or processed in ways that cause cross-contamination. Certified GF oats have been carefully handled to avoid this. I like Bob’s Red Mill and Trader Joe’s brands.
  • CHOCOLATE CHIPS. We’re dairy free, so I opt for allergy-friendly or dairy free chocolate chips. These and these are my favorites and are fairly widely available. I can find them at Kroger, Target, Walmart, Sprouts, Safeway, etc.
  • CANDY COATED CHOCOLATES. We’re gluten and dairy free, so traditional M&Ms won’t work for us. But, after a little looking, we actually found TWO brands that make a gluten free & vegan option. UNREAL and Little Secrets carry several varieties that are gluten and vegan. I like UNREAL quinoa crispies (so do my quinoa-hating kids!), and Little Secrets dark chocolate. Use what you can find, or feel free to use regular M&Ms if you don’t have to avoid dairy!
Monster Cookie Bars on white parchment
Stack of Flourless Monster Cookies Bars with gooey centers.

DOUBLE CHECK YOUR PAN. These monster cookie bars can be made in an 8×8″ or a 9×9″ baking dish. You’ll want to be sure you know what size you’re using since an 8×8″ pan will take longer to bake (since the cookies will be a bit thicker) and the 9×9″ pan will cook faster (since they’re slightly thinner).

PS – need a pan? I love this one. It’s gorgeous and looks upscale, but with a Target price tag!

WHERE DO YOU FIND DAIRY FREE M&Ms? I’ve had good luck with UNREAL and Little Secrets brands. They carry gluten & dairy free options and both use natural coloring (from plants not dye!). I can find them at Sprouts, Natural Grocers, Amazon, Whole Foods, and Thrive Market. You can use any dairy free variety you like–dark chocolate and quinoa crispies are our faves. If dairy isn’t a problem for you, feel free to use regular M&Ms. You can change out the colors to match the holidays–Valentine’s Day, Halloween, Christmas, Easter, 4th of July, etc.!

WHAT ARE THE BEST DAIRY FREE CHOCOLATE CHIPS? We have great luck with Enjoy Life and Tollhouse Simply Delicious, which are both allergy friendly. These ones also taste AMAZING and don’t contain any dairy ingredients (but are made on shared equipment).

PSST! TRY THIS ON TOP! My FAVORITE way to finish these is with a tiny sprinkle of coarse sea salt flakes. SO GOOD.

Flourless Monster Cookie Bars cut into squares


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Close up view of Flourless Monster Cookie Bars from One Lovely Life

Flourless Monster Cookie Bars (Gluten Free, Dairy Free)

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5 from 2 reviews

  • Author: Emily from One Lovely Life
  • Total Time: 37 minutes
  • Yield: 16 squares 1x


These delicious peanut butter blondies are studded with rolled oats, chocolate chips, and chocolate candies. Plus, they’re gluten free and dairy free! The perfect easy treat to satisfy your sweet tooth.  

(Recipe adapted from Ambitious Kitchen)



For The Flourless Monster Cookie Bars:

  • 1 cup natural peanut butter, room temperature*
  • 2 eggs
  • 1/2 cup coconut sugar
  • 1/4 cup pure maple syrup
  • 1 Tablespoon coconut oil
  • 1 1/2 teaspoons vanilla extract
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1/4 cup rolled oats (certified gluten-free oats, if needed)
  • 1/4 cup semi-sweet or dark chocolate chips**
  • 1/4 cup candy-coated chocolate candies (like M&Ms. See notes for GFDF options)

Optional (to top):

  • 1 Tablespoon each chocolate chips + candies
  • A pinch coarse sea salt flakes


  1. Preheat the oven to 350 degrees F.
  2. Line an 8×8 or 9×9″ baking pan with parchment paper.
  3. In a large bowl, combine peanut butter, eggs, coconut sugar, maple syrup, coconut oil, and vanilla. Stir until well combined.
  4. Then, sprinkle baking soda, salt, rolled oats, chocolate chips, and candies over the wet ingredients. Stir until mixed in.
  5. Pour the batter into your prepared baking pan, and use a spatula to spread out the dough. (It’ll be quite thick and sticky.)
  6. Sprinkle with 1 Tbsp extra chocolate chips and candies (optional–but it makes them look pretty!)
  7. Bake at 350 degrees for 18-22 minutes (for 9×9″pan) or 20-24 minutes (for 8×8″ pan), or until the center is nearly set and the edges are golden.
  8. If desired, sprinkle immediately with coarse sea salt flakes.
  9. Allow the cookie bars to cool before slicing into 16 squares. Store leftovers in an airtight container in the fridge or store in the freezer up to 1 month.


*Natural peanut butter should contain ONLY peanuts or ONLY peanuts and salt. No added oils or sugars.

**Our favorite allergy friendly chocolate chips are Enjoy Life brand or Tollhouse Simply Delicious

***Two dairy free/gluten free M&M-type candy options are: Little Secrets Dark Chocolate or UNREAL quinoa crispy candies.

  • Prep Time: 15 minutes
  • Cook Time: 22 minutes
  • Category: Dessert, Cookies, Bars
  • Method: Baking
  • Cuisine: American

Originally shared June 2019. Updated June 2022.

Adapted from Ambitious Kitchen


  1. I made these with flax eggs and all chocolate chips (no candy pieces) and they turned out great! I used a 9×9 and had to bake them a full 22 min. I probably could have gone a little longer as mine are a bit more crumbly than the photo. I wonder if the egg substitute caused that but either way they are delicious! About three months ago I started avoiding yeast, dairy and almond and this is my first cookie since. Thank you for a great recipe to bring a treat back into my life!

  2. I made the vegan version and they were delicious!! Kids loved them and plus, they’re an easy breakfast treat (peanut butter and oats counts as breakfast, right?)

    1. Sharon – Great question! You don’t blend the oats first. They’re just stirred into the batter whole and then they kind of blend in (which is why you can’t really see them in the photos.) If you look at the video (which pops up in a little box), you can see this step visually, too! Hope that helps! 🙂

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