If you like the classic cookie, you’ll LOVE this monster cookie bars recipe. These no flour monster cookie bars are loaded with chocolate chips, M&M’s, peanut butter chips. These bars are thick, chewy and completely delicious!
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If you love the classic jumbo monster cookies, made with oatmeal, peanut butter, M&M’s and chocolate chips, then this monster cookie bar recipe is for you!
Made with all your favorite monster cookie ingredients, but baked in a single sheet pan. This cookie bar recipe has all the flavors of your classic cookie favorite, but without all the work of making individual cookies.
In this post I’ll show you what you need for making monster cookie bars, ingredient substitutions, best tools for making cookie bars and tips on getting a soft and chewy bar every time.
What do I need to make monster cookie bars?
Here’s a quick reference check list of the ingredients you’ll need to make these sweet cookie bars:
- Oatmeal – I’ve found that instant oats are best for making these bars. You can also substitute (non-instant) Old Fashioned Rolled Oats.
- Peanut Butter – I recommend using creamy peanut butter, however, if you prefer chucky peanut butter and having small bits of peanuts in the cookie dough, feel free to use it instead.
- Butter – salted or unsalted butter.
- Eggs – large, room temperature eggs are ideal.
- Vanilla – vanilla extract will give these bars great flavor.
- Granulated Sugar – traditional in most cookie bar recipes.
- Brown Sugar – also, a traditional sweetener and also provides cookies the the beautiful golden color.
- Baking Soda – a necessary leavening to help the bars rise slightly.
- Salt – ideal for enhancing the flavor and sweetness. Don’t leave this out!
- Mini M&M candies – mini M&M’s are great for baking, but you can also use regular sized M&M’s.
- Semi-Sweet Chocolate Chips – I used a larger semi-sweet chocolate chip, however, you could also use dark or milk chocolate chips.
- Peanut Butter Chips – a great addition, peanut butter chips provide a little extra peanut butter flavor and richness to the bars.
For exact ingredient amounts and full recipe instructions, be sure to scroll down to the bottom of this post to the recipe card. Thanks!
Love a sweet treat? Check out our Campfire Smores Nachos which are a quick way to enjoy smores using the oven or a grill.
How do I make no flour monster cookie bars?
Start by creaming together the butter, peanut butter, granulated sugar and brown sugar. You can do this manually or with a hand or stand mixer. Add in the eggs and vanilla and mix until creamy.
In a separate bowl, mix together the dry ingredients; oatmeal, salt and baking soda. Gradually work the dry ingredients into the wet ingredients. The mixture will become thick, so you’ll like need to mix with a wooden spoon by hand.
Mix in the M&M’s, chocolate chips and peanut butter chips into the dough. It is best to mix these in manually with a wooden spoon.
Spread the dough evenly into a lined 15″ pan and bake at 350 degrees.
What pan is best for baking cookie bars?
Cookie bars are best in a 15″ jelly roll pan. This pan will have a short 1″ side. This type of pan is also great for making sheet cakes.
Should I line a pan before adding the cookie dough?
Lining a pan with parchment paper is beneficial for a couple of reasons. Parchment paper will help the cookie bars bake and brown evenly.
The paper will also help to easily remove the bars from the pan, as it provides a non-stick baking surface. If you wanted to lift out the entire batch of bars at once and cut on a cutting board, you can easily do that when the pan is lined with parchment paper.
How long do I bake a monster cookie bars recipe?
Monster cookie bars need to bake for 22-24 minutes at 350 degrees.
Why are cookie bars better than making individual cookies?
The benefit to making cookie bars versus traditional cookies is that it’s much easier and less time consuming to make bars. With cookies, you need to scoop and form individual cookies baking several batches at a time.
With cookie bars you only need one pan, making only one batch of bars. Additionally, cookie bars take take less than an hour from start to finish. A batch of cookies will usually take upwards of 2-3 hours to finish baking off all the cookies.
FAQ’s about making a monster cookie bars recipe:
Cookie bars can often end up hard and brittle because they have been overbaked. Cookie bars typically need only 22-24 minutes to bake.
Don’t overmix or over-beat the batter. Make sure you have an adequate amount of peanut butter and eggs to keep the batter moist. Lastly, don’t overbake the bars. Once they are slightly golden brown, promptly remove from the oven.
Semi-sweet chocolate chips are ideal for monster cookies and bars. Using a larger chip or even chocolate chunks is preferable, as the larger size bars can allow for a bigger chip. You can also use semi-sweet, dark chocolate or even white chocolate chips.
Because you are using oatmeal for the majority of the dry ingredients, flour is not necessary. The oats will give the bars a moist, chewy texture.
Love these no flour monster cookie bars? Check out our other cookie bar recipes:
- M&M Oatmeal Cookie Bars
- Chocolate Cake Mix Cookie Bars
- M&M Cookie Bars
- Chocolate Peanut Butter Brownies
- Red White and Blue Sugar Cookie Cake
- Healthy Banana Brownies
- Chocolate Chip Peanut Butter Oatmeal Bars
- M&M Brownies in a Jar
- Chocolate Caramel Pretzel Bars
- Starbucks Cranberry Bliss Bars
- Pumpkin Spice Sugar Cookie Bars
- Funfetti Frosted Sugar Cookie Bars
- German Chocolate Cookie Bars at Real Housemoms
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Monster Cookie Bars
Equipment
- 15 x 10 Pan Ideal for baking cookie bars and sheet cakes.
- Mixing Bowls These stainless steel mixing bowls are an essential cooking tool for every kitchen.
Ingredients
- 1/2 cup butter salted or unsalted
- 3 eggs
- 1 cup brown sugar
- 1 cup granulated sugar
- 1 1/2 cup creamy peanut butter
- 1 teaspoon vanilla
- 4 1/2 cups oatmeal instant or old fashioned rolled oats
- 1 teaspoon salt
- 2 teaspoons baking soda
- 1 cup semi-sweet chocolate chips like Ghirardelli 60% chocolate baking chips
- 1 cup mini M&M candies or regular plain M&M's
- 1 cup peanut butter chips
Instructions
- Preheat oven to 350 degrees. Line a 15" baking sheet with parchment paper. Set aside.
- In a large mixing bowl, cream together the butter, eggs, sugars, peanut butter and vanilla.
- In a separate bowl, combine the oatmeal, salt and baking soda. Gradually add the oatmeal mixture to the wet ingredients. Fold in the chocolate chips, M&M’s and peanut butter chips. Batter will be thick.
- Pour out the batter into the lined baking pan. Spray hands with non-stick cooking spray and press evenly into the lined pan, making sure that the batter is evenly spread into the corners and sides.
- Bake at 350 for 22-24 minutes. Don’t overbake. Let cool completely before cutting the bars. Enjoy!
Catherine says
Dear Erin, these cookie bars are outrageous! I love the rich, chewy texture..I can only image just how good these are. Pinned for later. xo, Catherine
Sandra says
My adult kids and grands would love these. They will be on my list for the holidays.
Sarah Eliza says
Mouth. Watering.
Those look amazing!
Found you via OMHG’s WW.
Danielle says
These cookies look delicious! What a creative way to make cookies! I want to share this in my weekly series called “Roll Out The Red Carpet Thursday” – I share bloggers’ amazing posts that I’ve found during the week. I hope that’ ok! Have a wonderful day! 🙂
Theresa @DearCreatives says
Oh, these would be easy & yummy to make. Thanks for sharing at the #InspirationSpotlight party. See you again soon. Pinned & Shared.
Beverly says
I haven’t made monster cookies in many years, but these look so great, I need to make them again.
Bev