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Full of chocolate chips, chewy oats, crunchy peanut butter, and M&M candies, Monster Cookie Bars are a fun, convenient twist on the old favorite. Monster Cookies have been my family’s favorite cookie ever since I was a child.
We use my grandmother’s monster cookies recipe and make a giant batch every year for our family’s camping trip. However, one year we simply ran out of time for our baking plans.
Monster Cookie Bars
I adjusted Grandma’s recipe slightly and pressed the cookie dough into the bottom of a large baking sheet. In less time than it would have taken to bake a single tray of cookies, the bars were cooling on the counter.
Easy as can be and the bars were a huge hit with everyone that tried them.
I was expecting a fun treat to snack on over the weekend, but these bars came close to trumping the original Monster Cookies.
Slightly more gooey than the cookies and still crisp on top and bottom, this is one of the best bar cookies I’ve ever tasted.
If you’re crazy for Monster Cookies like I am, try out Monster Cookie Ice Cream swirled with chunks of peanut butter and loaded with cookies. It will leave you craving just one more bite every time you make it.
Chewy oats, peanut butter cookie dough, brown sugar, and butter all combine to create these chocolate and m&m filled snackable Monster Cookie Dough Bites.
Bite-size chunks of Monster Cookie dough are more irresistible than ever when tucked into the Best Ever Cookie Dough Ice Cream.
And don’t forget Monster Cookie Ice Cream Sandwiches! Chewy peanut butter oatmeal chocolate chip cookies are layered on each side of a scoop of pure vanilla ice cream. These sandwiches are a perfect summer dessert, or snack, or meal all by themselves.
Monster Cookie Bars Recipe
To make this recipe, you’ll need the following ingredients:
- butter
- white sugar
- brown sugar
- eggs
- baking soda
- vanilla extract
- maple syrup
- crunchy peanut butter
- old fashioned rolled oats
- chocolate chips
- M&Ms
Monster Cookies
Preheat the oven to 350°F. Beat together the butter and sugars. Add the eggs, vanilla, syrup, and baking soda.
Stir in the peanut butter. Add the oats and stir again until well combined. Mix in the chocolate chips.
Press the dough into the bottom of a large baking sheet, or jelly roll pan. Top with the m&ms and lightly press them into the dough.
Bake for 16-17 minutes, until the bars are lightly browned and just past looking wet on top. They will not be firm, but they will set up as they cool.
Bar Cookie Recipes
If you’ve been hanging out with me for long at all, you know my long for EASY desserts. Dessert Bars are a terrific way to feed a crowd.
Almond Joy Brownies are an impressive dessert when topped with Homemade Ice Cream and Hot Fudge Sauce.
Cinnamon Pecan Shortbread Bars are perfect with a cup of coffee and I love having them stashed in the freezer.
Check out all of the Gluten Free Dessert Recipes on this website!
Monster Cookie Bars
Ingredients
- ⅔ cup butter room temperature
- 2 cups light brown sugar
- 1⅓ cups white sugar
- 4 eggs
- 1½ teaspoons baking soda
- 1 teaspoon vanilla extract
- 1 tablespoon maple syrup
- 2 cups crunchy peanut butter
- 6 cups old fashioned oats
- 1 cup semi-sweet chocolate chips
- ½ cup m&m candies for topping
Instructions
- Preheat the oven to 350°F. Beat together the butter and sugars. Add the eggs, vanilla, syrup, and baking soda. Stir in the peanut butter. Add the oats and stir again until well combined. Mix in the chocolate chips.
- Press the dough into the bottom of a large baking sheet, or jelly roll pan. Top with the m&ms and lightly press them into the dough. Bake for 16-17 minutes, until the bars are lightly browned and just past looking wet on top. They will not be firm, but they will set up as they cool.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
{originally published 7/24/14 – recipe notes and photos updated 11/20/24}
I love how simple these are and that they have no flour – I'm making these today!
Just remember these are only GF if you use oats that are certified GF.
Thank you! I came on here to say just that!
How large is your jelly roll pan/sheet pan?
Thank-you
My sheet cake pans (jelly roll pans) are about 18" x 12" – I hope that helps!
Should these cool in the pan? If so, for how long? Thanks!
I usually leave them in the pan and simply serve them from it. I'd let them cool completely before slicing.
Can I make these without the peanut butter? What would you recommend?
You can use an alternate nut butter. Almond or sunflower should work great.
Sunbutter and baking soda creates green FYI. Supposedly, it helps to decrease the baking soda by 1/3. I haven’t tried these that way yet.
If in Australia, m&m's contain gluten, so source American m&m's or use something different
Unless American M&M's packaging specifically states Gluten Free, I'd be catious. Some candy coatings contain thickeners, which contain gluten.
Do you need to grease the pan or would parchment work well?
Parchment works perfectly. It isn't required though. There is no need to grease the pan for this recipe.
I think I’m going to love this recipe and I’m sure that my gluten free grandchildren will also! Do these freeze well?
They freeze perfectly. Enjoy!
Love your blog Site! Would quick oats work as well?
Thank should work fine. The texture will be smoother and not as defined with the oats that way.
These were a hit at the church meal! I left out the peanut butter and M&Ms because of allergies and decreased the oats by 1/2 cup. They were so good! Thank you!
Really good! Made them for my daughters’ birthday party and got praises by everyone. Will repeat for sure.
I’m so happy that you enjoyed the recipe!
I made the version in your Weeknight Dessert Cookbook and they are a huge hit! My co-workers are freaking out! But the recipe is different (fewer ingredients and an 8×8 pan). Do you have that version of the recipe posted on the blog or is it just in the book?
I’m THRILLED that you love the cookie bars, Amanda! The recipes are very similar. I don’t have both of them online though.
So easy to make, family favorite! Usually make into cookies!
I’m glad you love them too, Ginalee!
These are soooo amazing! Thanks for the recipe. My gluten free friends LOVED them and so did we.
I’m so glad that you love the cookie bars, Julie!
So easy to make and the recipe yields a big tray of bars. Everyone loved them.
I’m glad you enjoyed them, Theresa!
these cookies were easy to make and are really good!
I’m glad you like them, Heather!
These were delicious! My only feedback is that it would be nice to have a size of pan (not just ‘large’) and that to be gluten free you must use gluten free oats! I added the M&Ms to the dough rather than on top and they were just as yummy, but maybe not as colorful as your picture! My husband loved them and I definitely will be making them again – in a 17×11 pan! 😉
A jelly roll pan is typically 12 by 18 inches, so your 11×17 is a great one to use. I’m glad you liked the bars!