Monster Cookie Bars – All the flavors of the classic monster cookie – peanut butter, oatmeal, chocolate chips, M&M’s,- but now in an easy-to-make bar!
Man, this year sure has flown by, hasn’t it?! I cannot believe we are already heading into October. Before you know it, we’ll be buying a Christmas tree and decking the halls!
As you are well-aware, I like to start each month with a new cookie recipe. Last month, I rang in the fall season with these Pumpkin Oatmeal Cream Pies. But for this month’s cookie, I am taking a break from fall and sharing a new take on a classic cookie – monster cookies, to be specific.
For today’s recipe, I am turning monster cookies into an easy-to-make bar. No need to form the dough into balls – simply dump the dough into a 9×13 baking pan and bake. Then, just slice and serve! You cannot get more simple than that!
Without further ado, here are my Monster Cookie Bars!
If you haven’t heard of or had a monster cookie before, let me explain exactly what it is. A monster cookie gets its name from the amount of ingredients that are in it. It’s an oatmeal cookie loaded with chocolate chips, peanut butter, and M&M’s – basically all my favorite things in one chewy dessert!
Instead of making cookies (which I’ave already done here), I wanted to make these cookies in bar-form. I love a great cookie bar – mostly because I get all the flavor and texture of a cookie but without all the effort. Rolling cookie dough into perfect balls before baking can get exhausting so this is a great alternative. Plus, you don’t have to chill the dough when making bars, which is another bonus!
This recipe is pretty straight-forward. But, as always, I have a few tips to help you along the way:
- The most important tip I can give you when making bars or brownies is to make sure you adjust your oven based on the type of baking pan you’re using. If you are using a dark-colored metal baking pan, always reduce the oven temperature by 25 degrees. This ensures that the center cooks just as evenly as the edges.
- Do not over-bake these bars! As soon as you see the edges getting golden brown, remove them from the oven. You don’t want these babies to get dry.
- Make sure you use quick-cooking oats, not instant oats. Instant oats will make these bars too mushy.
And there you have it – this month’s cookie recipe! What other kinds of cookies are you baking this month? Let me know in the comments below!
Monster Cookie Bars
Ingredients
- 1 stick butter unsalted, softened
- 1 cup light brown sugar
- 1/2 cup creamy peanut butter
- 2 large eggs
- 1 teaspoon pure vanilla extract
- 1 3/4 cups all-purpose flour
- 1 teaspoon baking soda
- 1 teaspoon salt
- 1 3/4 cups quick-cooking oats
- 3/4 cup semi-sweet chocolate chips
- 1 cup mini M&M's
Instructions
- Preheat oven to 350 degrees. Line 9x13 pan with parchment paper. Set aside.
- Beat butter and sugar together in a large bowl of a stand mixer until creamy. Add peanut butter and vanilla and combine. Add eggs one at a time until combined.
- In a separate medium bowl, add flour, baking soda, salt, and oats. Whisk until combined. Add dry ingredients to mixer and mix on low just until combined. Add chocolate chips and 1/4 cup of M&M's. Mix just until evenly distributed in dough.
- Scoop dough into prepared baking pan. Using your hands, press dough firmly in pan to spread it evenly. Sprinkle remaining 1/2 cup of M&M's over dough and press them into dough.
- Bake for 14-16 minutes, or until edges are browned and center is cooked. Remove from oven and let them cool for at least 10 minutes before cutting.
Notes
Pin for later:
More recipes you’ll love:
Monster Cookies
Pumpkin Oatmeal Cream Pies
Reese’s Pieces Peanut Butter Cookies
I’d like to divide this into two 8×8 pans. How would the bake time change if I did that?
I haven’t made these in smaller pans but first try reducing by 10-15 minutes and then just monitor so they don’t over bake
Oh man! These look so good. I need a big slice with some hot chocolate right now. The kids would go crazy for these too.
I love these monster bars! They are perfect for entertaining and sharing during the holidays!
I love the idea of an oatmeal cookie bar….adding peanut butter and M&Ms is a decadent idea, of which I wholly approve. Do you think i could get by with just greasing the pan if I’m short on parchment?
I’ll always take a cookie bar over a cookie — and especially when they’re packed with so many delicious things. Oatmeal, chocolate chips, AND m&ms? Yes, please!
These bars have my name written all over it. I love Monster Cookies, I am sure I would love these!
Didn’t know about monster cookies but I’m loving the idea of turning them into cookie bars. Less work and excellent result!
These bars look delicious! I never think about turning my cookies into bars, but it seems like it would be so much easter. Thanks for the oven temp tip!
I love this easy bar version of a classic cookie. My daughters love M&M’s, so I think I’ll make this with them!
These monster cookie bars are calling my name! I love mini M&Ms in baking and I love cookies in bar form. These look really delicious!
Cookie bars!!! These are the dessert that I lose count of how many I eat because they’re so delicious. Having my own recipe will be dangerous…
These look like a perfect afternoon snack with a cup of tea! I love how fun they are!
Yum! My son would love these. And my husband. And me! 🙂 I love M&M’s and oaty biscuits are completely my thing. Thanks for the handy tips on making these, too!
I can’t believe it is October already! These bars look like such a fun recipe. I’m sure they will be a hit with my family.
I’ve actually never heard of a monster cookie, but these bars look perfectly chewy and delicious. I know of a few kids who would go crazy for these! Thanks for sharing.
This monster cookie bars are so much fun perfect option or Halloween! My grandson loves M&Ms, and his birthday is coming soon I will surprise him with this monster cookies and ice cream =)
These monster cookie bars look sooooo good. I wish I had one right now along with a glass of milk.
I’ve always loved M&Ms so this sweet treat is something I would love to try! These monster cookie bars look delicious!
Love monster cookies, this is so great to put them in bar form!
This is such a great idea – take a beloved cookie and make it EASIER, in a quick and simple bar form! I mean, who doesn’t love monster cookies, right?!? But I’m all about making things faster and easier – this is a great solution! Terrific tips, too – about using the right oats and adjusting baking temps for different pans – so helpful!
Yum! That looks really good! I need to make some this weekend!
Such a tasty treat, it looks fun and delicious!
This sounds so yummy, I need to try this recipe