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You are here: Home / Recipes / Small-batch Monster Cookie Bars

Small-batch Monster Cookie Bars

05/07/20 | Bars, Brownies & Blondies, Desserts, Recipes, Small-batch Dessert

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These flourless Small-batch Monster Cookie Bars are easy to make and come out gooey, peanut buttery, and perfect every time. 

Craving something sweet and peanut buttery but don’t have any flour in your cupboard? You should make a little batch of monster cookie bars…

Overhead photo of small batch of Monster Cookie Bars.

Easy No-flour Cookie Bars

These small-batch monster cookie bars are a super simple one-bowl dessert that requires zero flour. They’re big on peanut butter flavor and packed full of M&Ms and melty chocolate chips.

Monster cookie bar recipes usually make an entire sheet pan of bars, but this small-batch recipe bakes in a loaf pan and makes just 6 to 8 cookie bars, which is probably good right now, because they are ridiculously addicting, and however many you make is probably how many you will eat. 😉

Monster cookie bars stacked on parchment paper.

What is their texture like? The texture of monster cookie bars is somewhere between a cookie and a (good) granola bar. Since there’s no flour, they’re not pillowy like a soft cookie.

Instead, they’re a little gooey and chewy, with a bit of crispiness around the outer edges and lots of texture from the oats.

A Note on Oats

I called for quick-cook oats in this recipe (AKA instant or minute oats) because these oats have been processed into smaller pieces for quicker cooking, and I prefer their texture in baked goods.

But you can use old-fashioned/rolled oats if that’s what you have on hand. The oat texture will just be slightly more aggressive.

You cannot use steel-cut oats in this recipe.

Small-batch monster cookie bars on parchment paper.

Notes & Substitutions

  • I don’t have a loaf pan: If you don’t have a standard-size 1-pound loaf pan, you can use a 5×7-inch baking dish, just extend the baking time slightly since your bars will be a bit thicker.
  • I don’t have M&M’s: The texture the crunchy candy shells add to these bars is really fantastic, so if you can get M&M’s, I recommend using them, but any baking chip (I bet peanut butter chips would be stellar) or chopped chocolate candy will work here as a substitution.
  • I don’t have oatmeal: Sorry, friend, you cannot substitute for or omit the oatmeal in these bars. If you don’t have oatmeal, give my Small-batch Peanut Butter Cookies a go. You can add 1/2 cup of M&Ms or chocolate chips and still get that chocolate and PB fix, no oatmeal required.
  • These bars need about 45 minutes to cool and firm up, otherwise they will fall apart when you try to cut and eat them. BUT if you really want to eat them warm and melty, scoop a serving into a bowl, add a scoop of ice cream and Fudge Sauce or Peanut Butter Sauce, maybe top with a little Whipped Cream and make a sundae out of it!

More Small-batch Recipes

  • Small-batch Chocolate Chip Cookies
  • Small-batch Brownies
  • Small-batch Banana Muffins
  • Small Red Velvet Cake
Overhead photo of small batch of Monster Cookie Bars.

Small-batch Monster Cookie Bars

These small-batch monster cookie bars are a super simple one-bowl dessert that require zero flour. They’re big on peanut butter flavor and packed full of M&Ms and melty chocolate chips.
5 from 2 votes
Print Pin
Course: Dessert
Cuisine: American
Prep Time: 10 minutes minutes
Cook Time: 15 minutes minutes
Cooling Time: 45 minutes minutes
Total Time: 1 hour hour 11 minutes minutes
Servings (Hover or Click to Change Yield): 6 to 8 bars
Calories: 381kcal
Author: Tracy

Equipment

  • 1-pound loaf pan
  • Parchment paper

Ingredients

  • 3 tablespoons (42g) salted butter softened*
  • 1/2 cup (132g) peanut butter creamy or chunky*
  • 1/3 cup (67g) granulated sugar
  • 1/3 cup (67g) brown sugar
  • 1 large egg
  • 1/2 teaspoon vanilla extract
  • 1 1/2 cups (130g) quick/instant oats *
  • 1/2 teaspoon baking soda
  • 1/2 cup (85g) M&M’s plus more for topping
  • 1/3 cup (56g) chocolate chips

Instructions

  • Preheat your oven to 350°F. Lightly grease and line a loaf pan with parchment paper.
  • In a medium bowl, combine softened butter, peanut butter, and granulated and brown sugars. Beat until well-combined and slightly lightened in color, about 1 minute.
  • Add egg and vanilla and mix until well-combined.
  • Add oats and sprinkle baking soda over the top. Mix until well combined.
  • Add M&M’s and chocolate chips and use a wooden spoon or spatula to mix.
  • Transfer mixture to prepared baking pan and press dough out into an even layer. Sprinkle a few extra M&M’s over the top if desired, and bake for 15 to 18 minutes, until the edges are lightly browned (the center will still look pale and slightly underdone). Do not overbake!
  • Allow bars to cool in the pan for about 45 minutes so they can firm up before transferring to a cutting board and slicing.
  • Serve and enjoy!

Notes

Store bars at room temperature in an airtight container for 3 to 4 days or freeze in a freezer bag for up to 2 months.
*If using unsalted butter, add 1/8 teaspoon of salt along with the oats and baking soda.
*These bars have not been tested with natural peanut butter. 
*Old-fashioned/rolled oats may also be used.
Nutritional information is for 8 servings.
Did you make this recipe?I'd love to see it! Tag @BakingMischief or hashtag it #BakingMischief.

This post may contain affiliate links, which means I receive a small commission if you make a purchase using them. There is absolutely no additional cost to you.

Comments | 3 comments

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Comments

  1. Fredrica Leuck says

    July 17, 2021 at 7:33 am

    5 stars
    These are delicious!!! I made them with natural peanut butter (because it’s the only kind I buy) and old fashioned oats following your directions on all measurements. I only had dark chocolate morsels to add so I improvised and added coconut as well. Took some to work and they have been bagging me ever since to make them again. Will take photo next time Thank you for all of your great recipes.

    Reply
  2. mpotter says

    May 12, 2020 at 8:32 am

    These look so yummy and easy enough for a quick dessert. Thank you!! Perfect for Weekend Movie Night!
    Can you please tell me why the “greasing” AND the parchment?
    I normally skip the greasing when I use parchment.

    Reply
    • Tracy says

      May 12, 2020 at 12:26 pm

      It’s really up to you if you want to do both, but I say grease and parchment paper because usually when you use parchment paper in a loaf pan you’re making a sling and only lining the two long sides so the short sides aren’t covered and can still stick. Also I find that the grease helps the parchment paper stick in place before filling, which I find convenient. Hope that makes sense!

      Reply
5 from 2 votes (1 rating without comment)

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Welcome!


Hi, I'm Tracy! Welcome to Baking Mischief, where we realize that not everyone is cooking every night for a family of four. We have delicious sweet and savory recipes, mostly scaled for one or two, and we love our pop culture around here, so keep an eye out for film, book, and TV-inspired treats as well! Read more»
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