Monster Cookie Bars Recipe

If you love treats that combine chewy oats, melty chocolate, and colorful candy with the perfect hint of peanut butter, then these Monster Cookie Bars are about to become your new obsession. They’re chewy, sweet, and packed with so much texture and flavor that every bite feels like a mini celebration. Whether you’re sharing with friends or keeping them all for yourself, Monster Cookie Bars deliver that nostalgic cookie experience in a convenient, easy-to-slice bar form. Trust me, once you try these, you’ll wonder why you didn’t make them sooner.

Ingredients You’ll Need

These ingredients are simple pantry staples but come together to create an extraordinary balance of flavor and texture. Each one plays a crucial role, from the creamy peanut butter adding richness, to the oats bringing wholesome chewiness, and the colorful m&m’s giving that irresistible pop of fun.

• Salted butter (1/2 cup, softened): Provides richness and moisture, plus helps with that soft, tender crumb.
• Peanut butter (1/4 cup): Brings a nutty depth and creamy texture that makes these bars stand out.
• Brown sugar (1 cup): Adds a deep, caramel-like sweetness that keeps the bars chewy.
• Granulated sugar (1/4 cup): Enhances sweetness and helps with slight crisp edges.
• Eggs (2): Bind everything together and contribute to the tender texture.
• Vanilla extract (2 tsp): Lifts the flavors and adds a warm, aromatic note.
• All-purpose flour (2 cups): The base that gives the bars structure without being too cakey.
• Rolled oats (1 cup): Adds chewiness and a hearty texture that’s essential for these cookies.
• Baking soda (1 tsp): Helps the bars rise slightly and contributes to tenderness.
• Baking powder (1/2 tsp): Works with baking soda to give the right balance of lift and softness.
• Salt (1/2 tsp): Enhances all the sweet flavors and balances the richness.
• Semi sweet chocolate chips (1 cup): Melts into gooey pockets of chocolate that everyone loves.
• M&M’s (3/4 cup): Provide colorful crunch and fun bursts of extra sweetness.

How to Make Monster Cookie Bars

Step 1: Prep Your Pan and Oven

Start by lining a 9×9 inch pan with parchment paper. This will make removing your bars a breeze and ensure they keep their perfect edges. Preheat your oven to 350 degrees Fahrenheit (180 degrees Celsius) so it’s hot and ready once your dough is mixed.

Step 2: Cream the Butters and Sugars

In a large bowl, beat together the softened butter, peanut butter, brown sugar, and granulated sugar until the mixture is smooth, creamy, and well combined. This step is key to creating a tender yet chewy texture that makes these Monster Cookie Bars so addictive.

Step 3: Add Eggs and Vanilla

Next, add the eggs one at a time and beat until fully incorporated, then stir in your vanilla extract. These ingredients help bind everything together and add moisture, keeping your bars soft rather than dry or crumbly.

Step 4: Combine Dry Ingredients

In a separate bowl, whisk together the flour, rolled oats, baking soda, baking powder, and salt. This blend gives structure and body to the bars while the oats add delightful chewiness.

Step 5: Mix Dry Ingredients Into Wet

Gradually mix the dry ingredients into the wet peanut butter mixture until you have a sticky dough. Don’t overmix here, you just want everything evenly combined to keep the bars tender and dense.

Step 6: Fold in Chocolate Chips and M&M’s

Stir in the chocolate chips and M&M’s gently but thoroughly so that every bite includes melty chocolate and bursts of colorful crunch. This step adds those classic Monster Cookie Bar personality traits that make them so fun to eat.

Step 7: Bake to Golden Perfection

Pour the dough into your prepared pan and use your hands or a spatula to press it into an even layer, packing it lightly but not too tightly. Bake at 350°F for 25-30 minutes until the tops are golden brown and just set. This timing gives you bars that are perfectly chewy—not underbaked or dry.

Step 8: Cool and Slice

Let the Monster Cookie Bars cool completely in the pan before lifting them out with the parchment paper. This cooling time is important so the bars firm up and cut cleanly into squares without crumbling.

How to Serve Monster Cookie Bars

Garnishes

While these bars stand on their own, a light dusting of powdered sugar or a drizzle of melted peanut butter on top can add a pretty finishing touch. You can also sprinkle a few extra M&M’s or chocolate chips on top just before baking for a colorful presentation that makes them impossible to resist.

Side Dishes

Monster Cookie Bars pair beautifully with a cold glass of milk or a scoop of vanilla ice cream for an indulgent dessert experience. If you want a lighter pairing, a cup of hot tea or coffee can complement the richness and sweetness perfectly without feeling too heavy.

Creative Ways to Present

Cut into smaller squares for a party platter, or stack thick bars with parchment paper in between for a grab-and-go snack pack. You can even cut bars into bite-sized pieces and serve them in small decorative cups for a fun finger-food dessert at gatherings.

Make Ahead and Storage

Storing Leftovers

Store leftover Monster Cookie Bars in an airtight container at room temperature to keep them soft and chewy for 3 to 4 days. If your kitchen is warm or humid, placing the container in the fridge can extend freshness, but the texture might firm up slightly.

Freezing

These bars freeze beautifully! Wrap individual pieces tightly in plastic wrap and place them in a resealable freezer bag or airtight container. When you want a treat, let them thaw at room temperature or pop them in the microwave for just a few seconds to enjoy the full gooey monster cookie magic.

Reheating

For that freshly-baked warmth, reheat Monster Cookie Bars in a microwave for 10 to 15 seconds or place them in a preheated oven at 300°F for 5 minutes. This brings back the melty chocolate and soft texture that makes them irresistible.

FAQs

Can I use crunchy peanut butter instead of smooth?

Absolutely! Crunchy peanut butter will add extra texture and little bursts of peanutty crunch inside the bars, which can be a delightful twist on the classic creamy version.

Are Monster Cookie Bars gluten-free?

The traditional recipe uses all-purpose flour and oats, so it’s not gluten-free. However, you can substitute with gluten-free flour and certified gluten-free oats to make a tasty gluten-free version.

Can I swap out the M&M’s for other candies?

Definitely! Feel free to get creative with your favorite candies like Reese’s Pieces, chopped-up peanut butter cups, or even dried fruit for a unique spin on Monster Cookie Bars.

How thick should I press the dough in the pan?

Press the dough evenly to about 1 inch thick in the 9×9 pan. This thickness ensures the bars bake evenly and hold together nicely with just the right chewiness.

Why did my bars come out too dry?

Dry bars usually mean they were baked too long or the dough was overmixed. Keep a close eye on your bake time and stop once the edges are golden and the center no longer looks wet. Also, stir until just combined to keep them tender.

Final Thoughts

There is something truly special about a bar that combines the best parts of your favorite cookies and candy in one delicious bite. Monster Cookie Bars are easy to make, fun to eat, and endlessly versatile, making them perfect for everyday treats or celebrations. I’m so excited for you to whip up a batch and share these with your friends and family—once you do, I promise they’ll be asking for the recipe too!

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