Welcome to the delightful world of Monster Cookie Bars! If you’re searching for a dessert that combines the best of all your favorite treats, then you’ve stumbled upon the right recipe. These cookie bars are an indulgent, sweet creation that brings together the rich flavors of peanut butter, chocolate chips, and colorful M&M’s, all nestled in a chewy oat base. Perfect for a family gathering, a school bake sale, or simply satisfying your sweet tooth, these bars are sure to become a new favorite in your household.
Each bite of Monster Cookie Bars is like a party in your mouth, with the creamy peanut butter and chocolatey goodness melding beautifully with the chewy oats. Whether you’re a cookie lover or a fan of bars, these treats are versatile enough to please anyone. Plus, they’re easy to make, requiring only one bowl and a few simple ingredients, making them a quick and delightful baking project. So grab your apron and let’s dive into this scrumptious recipe!
Why You’ll Love This Recipe
There are countless reasons to adore Monster Cookie Bars, and here are just a few:
- Quick and Easy: With minimal prep time and just one bowl needed, these bars are perfect for a busy day. Whether you’re baking for a crowd or just for yourself, you’ll love how simple they are to whip up.
- Deliciously Versatile: Feel free to customize your bars! Swap out chocolate chips for white chocolate, or use different candies instead of M&M’s. You can even add nuts for an extra crunch!
- Perfect for Any Occasion: These cookie bars are a hit for birthdays, holidays, or just a sweet treat for a cozy night in. They’re great for sharing, but you might want to keep them all to yourself!
- Chewy and Satisfying: The combination of oats and peanut butter creates a chewy texture that is incredibly satisfying. You’ll find it hard to stop at just one piece!
- Kid-Friendly: Kids love these bars! They are easy to grab and eat, making them a great snack or dessert option for children. Plus, they can help with the baking process!
Why You Should Try This Recipe
When it comes to baking, the right recipe can make all the difference. Here’s why you should try these Monster Cookie Bars:
- Healthier Ingredients: While these bars are undoubtedly a treat, they incorporate oats and peanut butter, which provide some nutritional benefits. Oats are a good source of fiber, and peanut butter offers protein and healthy fats.
- Family Bonding: Baking together is a wonderful way to create memories with family or friends. This recipe is simple enough for kids to join in, making it a fun activity for everyone.
- Make Ahead: These bars store well, so you can make them in advance for upcoming events or simply to have on hand for snacks throughout the week. They stay fresh and delicious for several days!
- Great for Meal Prep: If you’re looking for healthy snack options, these bars can be cut into smaller pieces, making them ideal for meal prep. Enjoy them throughout the week without the guilt!
- A Crowd-Pleaser: Whether you’re sharing them at a potluck or serving them at home, these bars are sure to impress. The combination of flavors and textures is a guaranteed hit with everyone!
Ingredients and Necessary Utensils
Before you dive into making your Monster Cookie Bars, let’s gather all the ingredients and tools you’ll need:
Ingredients
- 1 cup unsalted butter, softened
- 1 cup brown sugar, packed
- 1 cup granulated sugar
- 1 cup creamy peanut butter
- 3 large eggs
- 1 teaspoon vanilla extract
- 3 cups old-fashioned oats
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 cup semi-sweet chocolate chips
- 1 cup M&M’s candies
Necessary Utensils
- Large mixing bowl
- Spatula or wooden spoon
- 9×13 inch baking dish
- Parchment paper (optional, for easier removal)
- Whisk (for dry ingredients)
- Measuring cups and spoons
- Wire rack (for cooling)
Having all your ingredients and tools ready will ensure a smooth baking process. Once you have everything, you’re just a few steps away from enjoying your delicious Monster Cookie Bars!
Detailed Recipe Steps
Now let’s get into the nitty-gritty of how to make these delightful Monster Cookie Bars. Follow these steps for a perfect bake:
- Preheat the Oven: Begin by preheating your oven to 350°F (175°C). This is an essential step as it ensures your cookie bars bake evenly. Grease a 9×13 inch baking dish or line it with parchment paper for easy removal later.
- Cream the Butters and Sugars: In a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar using a spatula or electric mixer until the mixture is light and fluffy. This step helps to incorporate air into the batter, resulting in a lighter texture.
- Add Peanut Butter: Next, mix in the creamy peanut butter until fully incorporated. This adds a rich flavor and creamy texture to your bars.
- Incorporate Eggs and Vanilla: Add the eggs one at a time, mixing well after each addition to ensure they are fully blended. Then, stir in the vanilla extract for an extra layer of flavor.
- Combine Dry Ingredients: In a separate bowl, whisk together the old-fashioned oats, baking soda, and salt. This will help distribute the baking soda and salt evenly throughout the batter.
- Mix Dry Ingredients with Wet Ingredients: Gradually add the dry oat mixture to the wet ingredients, mixing until just combined. Avoid over-mixing, as this can make the bars tough.
- Fold in Chocolate Chips and M&M’s: Gently fold in the semi-sweet chocolate chips and M&M’s until they are evenly distributed throughout the batter. This is where the fun comes in – the colorful M&M’s add a festive touch!
- Spread in Baking Dish: Pour the batter into your prepared baking dish and spread it evenly with a spatula. Make sure to smooth the top so that the bars bake evenly.
- Bake: Place the baking dish in the preheated oven and bake for 25-30 minutes. Keep an eye on them, and look for the edges to be golden brown and a toothpick inserted in the center to come out with a few moist crumbs.
- Cool and Cut: Once baked, allow the cookie bars to cool in the pan for about 10 minutes. Then, transfer to a wire rack to cool completely. Once cooled, cut into squares and serve!
Pro Tip: For an extra indulgent treat, serve these bars warm with a scoop of vanilla ice cream on top. You won’t regret it!
FAQs
What are Monster Cookie Bars?
Monster Cookie Bars are a delicious dessert made with a combination of creamy peanut butter, oats, chocolate chips, and M&M’s, all baked into a chewy bar. They are easy to make and are perfect for any occasion!
Can I make Monster Cookie Bars ahead of time?
Yes! Monster Cookie Bars can be made ahead of time. Once cooled, store them in an airtight container for up to a week, making them a great option for meal prep or gatherings.
Can I substitute ingredients in Monster Cookie Bars?
Absolutely! You can substitute the chocolate chips for white chocolate or butterscotch chips, and swap out M&M’s for your favorite candies or nuts. Feel free to get creative!
How do I store leftover Monster Cookie Bars?
Store any leftover Monster Cookie Bars in an airtight container at room temperature for up to a week. You can also freeze them for longer storage. Just make sure to wrap them tightly!
Conclusion
In summary, Monster Cookie Bars are a fun and delicious treat that everyone will love. With their chewy texture, rich flavors, and colorful appeal, they are sure to become a favorite in your home. Whether you’re baking them for a special occasion or just to satisfy your sweet tooth, these bars are easy to make and even easier to enjoy.
We hope you give this recipe a try and share your thoughts in the comments below! Don’t forget to share this recipe with your friends and family, and check out our other delightful recipes for more sweet inspirations, such as our Strawberry Pound Cake and Gingerbread Cheesecake Cookies. Happy baking!
For more delicious recipes and inspiration, be sure to follow us on Pinterest: Chef Boiardi Recipes.

Monster Cookie Bars
Ingredients
Equipment
Method
- Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking dish or line it with parchment paper for easy removal.
- In a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until the mixture is light and fluffy.
- Mix in the creamy peanut butter until well combined.
- Add the eggs one at a time, mixing well after each addition. Then, stir in the vanilla extract.
- In a separate bowl, whisk together the oats, baking soda, and salt.
- Gradually add the dry oat mixture to the wet ingredients, mixing until just combined.
- Gently fold in the semi-sweet chocolate chips and M&M's candies until evenly distributed throughout the batter.
- Pour the batter into the prepared baking dish and spread it evenly with a spatula.
- Bake in the preheated oven for 25-30 minutes, or until the edges are golden brown and a toothpick inserted in the center comes out with a few moist crumbs.
- Allow the cookie bars to cool in the pan for about 10 minutes before transferring to a wire rack to cool completely. Once cooled, cut into squares and serve.