The Best Monster Cookie Bars
These delicious Monster Cookie Bars are one of my favorite treats. They are fully loaded with peanut butter, chocolate chips, and M&Ms, and come out perfectly thick and chewy every time. They are always a huge hit and never last long when I make them!
For more easy Dessert Recipes, be sure to check out my Cherry Chocolate Cake, Air Fried Apples, and Kool Aid Pie.
If you’re a fan of monster cookies, then you are going to love these super delicious and chewy monster cookie bars!
They are chock full of good things: peanut butter, oats, chocolate chips, and M&Ms, to name a few. They taste like an amazing combination of oatmeal cookies and peanut butter cookies with M&Ms thrown into the mix. And they are so SO GOOD!
Seriously, my kids absolutely love these monster bars and devour them whenever they’re in the house.
The ingredients are also very versatile. Feel free to replace any of the fillings in these dessert bars with something like reese’s pieces, white chocolate chips, or even leftover Halloween candy instead.
I also have recommendations for what to use if you’re looking for a peanut butter alternative. We have a peanut allergy in my house, so I’ve got some ideas for you if you have the same!
Ingredients for Monster Cookie Bars
- Butter – you will need two sticks of unsalted butter.
- Peanut butter – I recommend using creamy peanut butter or natural peanut butter.
- Sugar – a combination of brown sugar and granulated sugar is what you will use.
- Eggs – two large eggs will bind your monster bars together.
- Vanilla – you can use vanilla extract or vanilla bean paste.
- Flour – plain, all purpose flour is all you’ll need.
- Oats – I recommend using old-fashioned oats instead of quick oats.
- Chocolate Chips – use one heaping cup of semi-sweet chocolate chips for your bars.
- M&M Candies – these will add so much color and sweet flavor to your monster cookie bars.
A full list of ingredients, measurements, and instructions are located in the recipe card below.
How to Make Monster Cookie Bars – Step by Step
In a large bowl, cream together the softened butter, peanut butter, and sugars. Stir in the eggs and vanilla.
Add in the dry ingredients and stir until just combined.
Add the chocolate chips and M&Ms.
Fold gently into the cookie dough.
Spray a 9×13 inch baking dish with cooking spray. Press the dough into the prepared baking pan.
Bake in the preheated oven for 30-35 minutes until bars are golden brown and set.
Tips and Notes
- Switch up the fillings. You can replace the chocolate chips with peanut butter chips, butterscotch chips, dark chocolate chips, or even nuts like walnuts or chopped pecans. You can also replace the M&M candies with another type of candy or use mini M&Ms.
- Peanut butter alternatives: If you’re looking for a peanut free version of monster cookie bars, consider making these with your favorite nut butter alternative like almond butter, cashew butter, etc. Just make sure whatever you choose is creamy, not crunchy. My favorite is Wow Butter; it’s made from soy, is peanut and tree nut free, and tastes GOOD! It has a similar peanut butter flavor, and bakes perfectly in the bars. You could also use sunflower seed butter, but the flavor profile will be very different.
- Make Monster Cookies instead! This dough can also be used for making cookies instead of bars. Simply line a sheet pan with parchment paper and use a cookie scoop to form the dough into balls. Bake the cookies for 10-12 minutes in a 350 degree oven until just set.
- Store fully baked and cooled cookies in an airtight container on the counter for up to four days.
If you try this recipe, please leave a comment and rating below. I love to hear from you and always appreciate your feedback!
Recipe: The Best Monster Cookie Bars
Ingredients
- 1 cup unsalted butter, 2 sticks
- 1 cup peanut butter, or nut butter alternative, *see notes
- 1 cup packed brown sugar
- 3/4 cup granulated white sugar
- 2 eggs
- 2 teaspoons vanilla extract
- 2 cups all purpose flour
- 2 cups old fashioned oats
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 cup semi-sweet chocolate chips
- 1 cup M&M candies
Instructions
- Preheat the oven to 350 degrees Fahrenheit. Spray a 9×13 inch baking dish with cooking spray and set aside.
- In a large bowl, cream together the softened butter, peanut butter, and sugars with an electric mixer until smooth and creamy, about two minutes. Scrape down the sides of the bowl as needed. Add in the eggs and vanilla and mix until blended.
- Add the flour, oats, baking soda, and salt and mix on low speed until just combined.
- Fold in the chocolate chips and M&Ms. Press the dough into the prepared baking pan using a spatula to smooth out the top.
- Bake in the preheated oven for about 30-35 minutes until bars are golden brown and set. Don't overbake. Allow to cool slightly before cutting and enjoying!
Notes
- Switch up the fillings. You can replace the chocolate chips with peanut butter chips, butterscotch chips, dark chocolate chips, or even nuts like walnuts or chopped pecans. You can also replace the M&M candies with another type of candy or use mini M&Ms.
- Peanut butter alternatives: If you’re looking for a peanut free version of monster cookie bars, consider making these with your favorite nut butter alternative like almond butter, cashew butter, etc. Just make sure whatever you choose is creamy, not crunchy. My favorite is Wow Butter; it’s made from soy, is peanut and tree nut free, and tastes GOOD! It has a similar peanut butter flavor, and bakes perfectly in the bars. You could also use sunflower seed butter, but the flavor profile will be very different.
- Make Monster Cookies instead! This dough can also be used for making cookies instead of bars. Simply line a sheet pan with parchment paper and use a cookie scoop to form the dough into balls. Bake the cookies for 10-12 minutes in a 350 degree oven until just set.
- Store fully baked and cooled cookies in an airtight container on the counter for up to four days.
This is really good; my kids approved it.
These were so delicious! Can’t wait to make again.
My whole family loved this monster cookie bar recipe. Looking forward to making it again!