If you’re on the hunt for a sweet treat that packs a punch of flavor, texture, and nostalgia, you’re going to fall head over heels for The Best Monster Cookie Bars Recipe. I absolutely love how these bars come together—chewy yet soft, loaded with peanut butter goodness, chocolate, and those colorful M&Ms that make every bite a little party. Trust me, once you try this recipe, it’ll become your new go-to for anytime you want a comforting, crowd-pleasing dessert that’s easy to whip up!
Why You’ll Love This Recipe
- Perfect Texture: These bars strike the ideal balance between chewy oats and soft, peanut buttery goodness.
- Super Customizable: You can swap mix-ins easily to match your favorite flavors or dietary needs.
- Kid-Approved: My family goes crazy for these bars – and they’re perfect for lunchboxes or after-school snacks.
- Simple and Quick: You’ll love how fast you can throw this together with minimal fuss, even on busy days.
Ingredients You’ll Need
Each ingredient plays a crucial role here, coming together to create the chewy, rich, and colorful monster cookie bars you’ll want to make again and again. I like using creamy peanut butter for the best texture, but you’ll see some great alternatives below.
- Unsalted butter: Softened butter keeps things rich without adding extra saltiness, helping balance the sweetness.
- Peanut butter or nut butter alternative: Creamy is key here; I’ve had great luck with almond butter too if you want a twist.
- Brown sugar: Packed brown sugar gives the bars their deep caramel notes and chewy bite.
- Granulated white sugar: Adds a hint of crispness and balances the molasses in the brown sugar.
- Eggs: They bind everything together and keep the bars tender.
- Vanilla extract: Just a touch elevates all the flavors beautifully.
- All-purpose flour: The base that holds all the good stuff together.
- Old fashioned oats: For that classic monster cookie chew and hearty texture.
- Baking soda: Helps the bars rise just enough without making them cakey.
- Salt: Enhances all the sweet flavors and balances richness.
- Semi-sweet chocolate chips: These little melty pockets of chocolate are a must for me – pure magic.
- M&M candies: Obviously, the colorful fun and extra crunch that make these bars stand out.
Variations
I love how flexible this recipe is. Whether you’re avoiding certain nuts or want to mix up the candies, it’s super easy to make these bars your own. Here are a few tweaks I’ve tried that I think you’ll enjoy experimenting with too.
- Nut Butter Swap: I once made these with sunflower seed butter for a peanut-free version and while the flavor was a bit different, they still satisfied everyone at the party.
- Chip Choices: Swapping semi-sweet chocolate chips for butterscotch or white chocolate chips adds a fun twist and keeps things interesting.
- Add Nuts: Chopped walnuts or pecans add a wonderful crunch and contrast to the soft oats and chocolate.
- Mini M&Ms: Using mini candies distributes the color and crunch throughout every bite, making the bars even more colorful.
How to Make The Best Monster Cookie Bars Recipe
Step 1: Get Your Oven and Pan Ready
First things first, preheat your oven to 350°F (175°C). Lightly spray a 9×13 inch baking dish with cooking spray so your bars come out cleanly and with that perfect edge. I like to do this step early because it saves time and keeps the process smooth.
Step 2: Cream Butter, Peanut Butter, and Sugars
In a large bowl, use an electric mixer to cream together the softened butter, peanut butter, brown sugar, and granulated sugar. This usually takes about two minutes until everything is smooth and creamy. Scrape down the sides of your bowl as you go to make sure everything is evenly combined—trust me, it makes a difference in the texture of your bars.
Step 3: Add Eggs and Vanilla
Once your butter mixture is perfect, add in the eggs and vanilla extract. Mix again until blended and smooth. The eggs help bind the dough and add moisture, so don’t skip this step!
Step 4: Incorporate Dry Ingredients
Time to add the flour, oats, baking soda, and salt. Mix on low speed just until everything comes together—you don’t want to overmix here because it can make your bars tougher. The oats bring in the chewy texture we all love, while the baking soda gives a gentle lift.
Step 5: Fold in Chocolate Chips and M&Ms
Grab a spatula and gently fold in the chocolate chips and M&M candies. This step is all about distributing the goodies evenly without breaking the candies too much. I like to reserve a few M&Ms to sprinkle on top before baking—it makes them look extra inviting!
Step 6: Bake to Perfection
Press the cookie dough evenly into your prepared pan using a spatula. Bake in the preheated oven for 30-35 minutes, or until the edges are golden and the center is set but still soft. Keep an eye on them after 30 minutes—you don’t want to overbake because then the bars lose their soft chewiness.
Step 7: Cooling and Serving
Once baked, let the bars cool in the pan for at least 15 minutes before slicing. This helps them set up so you get clean bars that don’t crumble. I found it best to use a sharp knife and wipe it clean between cuts for the neatest bars.
Pro Tips for Making The Best Monster Cookie Bars Recipe
- Use Room Temperature Ingredients: I always make sure my butter and peanut butter are softened to room temperature—it blends so much better and yields a smoother dough.
- Don’t Overbake: Watch the edges closely near the 30-minute mark; overbaking steals that soft chew we all love.
- Mix-ins on Top: Saving a few M&Ms to press on top pre-baking makes the bars look irresistible and adds a colorful finish.
- Even Pressing: Press the dough firmly but evenly in the pan so the bars bake uniform and slice cleanly.
How to Serve The Best Monster Cookie Bars Recipe
Garnishes
I usually keep the garnishing simple—just a light dusting of powdered sugar if I’m feeling fancy or a handful of extra M&Ms sprinkled on top after cooling for a fun pop of color. Sometimes I add a drizzle of melted chocolate for a touch of elegance, especially when sharing with friends.
Side Dishes
These bars are a star on their own, but if you want to pair them, a scoop of vanilla ice cream or a glass of cold milk pairs perfectly. I also love serving them with fresh berries to balance out the richness.
Creative Ways to Present
For special occasions, I’ve cut these bars into bite-sized squares and arranged them on a platter with colorful cupcake liners—everyone loved the bite-sized treat approach! Wrapping individual bars in parchment paper tied with twine also makes an adorable homemade gift.
Make Ahead and Storage
Storing Leftovers
I store leftover bars in an airtight container at room temperature, and they stay fresh for about 4-5 days. Just keep them away from heat to avoid melting the chocolate or M&Ms.
Freezing
These monster cookie bars freeze beautifully! I slice them into bars first, then wrap each piece tightly in plastic wrap before placing them in a freezer-safe bag. When I want one, I pop a bar in the fridge overnight to thaw—super convenient for busy days.
Reheating
To warm up a bar, I heat it in the microwave for just 10-15 seconds—long enough to soften the chocolate without making the bar soggy. If you prefer, a quick 5-minute warm-up at 300°F in the oven works great too.
FAQs
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Can I make The Best Monster Cookie Bars Recipe without peanuts?
Absolutely! I often substitute peanut butter with almond butter, cashew butter, or soy-based alternatives like Wow Butter, which is great if you’re avoiding peanuts and tree nuts. Just make sure your alternative is creamy for the best texture.
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How do I avoid overbaking the bars?
Keep an eye on the oven timer once you hit about 30 minutes. The edges should be golden but the center still a bit soft. The bars will firm up as they cool, so err on the side of slightly underbaking.
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Can I use quick oats instead of old fashioned oats?
Old fashioned oats are best because they add that classic chewy texture. Quick oats might make the bars softer and less textured, but it’s doable if that’s what you have on hand.
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Can I turn this recipe into cookies instead of bars?
Definitely! This dough makes fantastic monster cookies too. Just scoop dough into balls, place on a parchment-lined sheet, and bake for 10-12 minutes at 350°F. I love how convenient and shareable the cookies are.
Final Thoughts
The Best Monster Cookie Bars Recipe holds a special place in my kitchen because it combines comforting flavors with a fun twist—the perfect snack to brighten any day. I remember making these for a family gathering, and every single person went back for seconds (or thirds!). I can’t wait for you to try them and see just how addictively good they are. So, grab your ingredients, get your oven warming, and treat yourself to these delicious bars—you deserve it!
Print
The Best Monster Cookie Bars Recipe
- Prep Time: 10 minutes
- Cook Time: 35 minutes
- Total Time: 45 minutes
- Yield: 24 servings
- Category: Dessert
- Method: Baking
- Cuisine: American
Description
These Best Monster Cookie Bars are a delightful blend of chewy oats, rich peanut butter, and sweet chocolate chips and M&Ms, baked into a deliciously soft bar. Perfect for satisfying your sweet tooth with a nostalgic twist, these bars are easy to make and versatile with options to customize the mix-ins for your preference.
Ingredients
Wet Ingredients
- 1 cup unsalted butter (2 sticks), softened
- 1 cup peanut butter or nut butter alternative (creamy, not crunchy)
- 1 cup packed brown sugar
- 3/4 cup granulated white sugar
- 2 eggs
- 2 teaspoons vanilla extract
Dry Ingredients
- 2 cups all-purpose flour
- 2 cups old fashioned oats
- 1 teaspoon baking soda
- 1/2 teaspoon salt
Mix-Ins
- 1 cup semi-sweet chocolate chips
- 1 cup M&M candies
Instructions
- Preheat and Prepare Pan: Preheat your oven to 350 degrees Fahrenheit. Spray a 9×13 inch baking dish with cooking spray to prevent sticking and set it aside.
- Cream Butter, Peanut Butter, and Sugars: In a large bowl, use an electric mixer to cream together the softened butter, peanut butter, and both sugars until the mixture is smooth and creamy. This should take about two minutes. Scrape the sides of the bowl as needed to ensure even mixing.
- Add Eggs and Vanilla: Add the eggs and vanilla extract to the creamed mixture and continue mixing until everything is fully blended.
- Combine Dry Ingredients: Add the all-purpose flour, old fashioned oats, baking soda, and salt to the bowl. Mix on a low speed just until all the dry ingredients are incorporated and there are no flour streaks.
- Fold in Chocolate Chips and M&Ms: Gently fold the chocolate chips and M&M candies into the dough using a spatula, ensuring even distribution without overmixing.
- Press Dough into Pan: Transfer the dough to your prepared baking dish and use a spatula to press and smooth the dough evenly across the bottom.
- Bake: Place the baking dish in the preheated oven and bake for 30 to 35 minutes, or until the bars are golden brown and set. Be careful not to overbake to maintain a soft texture.
- Cool and Serve: Allow the bars to cool slightly in the pan before cutting into squares and serving to enjoy the perfect chewy texture.
Notes
- You can customize the fillings by substituting the chocolate chips with peanut butter chips, butterscotch chips, dark chocolate chips, or nuts like walnuts or pecans. Similarly, swap M&Ms with other candies or mini M&Ms for variety.
- For a peanut-free version, use creamy nut butter alternatives such as almond butter, cashew butter, sunflower seed butter, or soy-based options like Wow Butter which mimics peanut butter flavor and texture.
- This dough is versatile and can be used to make cookies instead of bars—just scoop dough balls onto a parchment-lined sheet pan and bake for 10-12 minutes at 350 degrees Fahrenheit.
- Store fully baked and cooled cookie bars in an airtight container at room temperature for up to four days for best freshness.
Nutrition
- Serving Size: 1 bar (1/24 of recipe)
- Calories: 220
- Sugar: 14g
- Sodium: 130mg
- Fat: 12g
- Saturated Fat: 5g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 26g
- Fiber: 2g
- Protein: 5g
- Cholesterol: 35mg
