If you’re craving something decadently rich with a playful twist, these Monster Cookie Fudgy Brownies are an absolute game changer. Imagine a dense, fudgy brownie base bursting with luscious chocolate intensity and then crowned with colorful, chewy monster cookie dough packed with oats, mini M&M’s, and chocolate chips. This combination creates an irresistible texture and flavor mashup that’s both comforting and fun to eat—perfect for sharing with friends, family, or simply indulging in a little celebration of the everyday. Trust me, once you try these, Monster Cookie Fudgy Brownies will be your new go-to treat for every occasion.

Monster Cookie Fudgy Brownies Recipe - Recipe Image

Ingredients You’ll Need

Gathering the right ingredients is crucial, but thankfully, this recipe keeps it straightforward and uses pantry staples that come together to create that perfect balance of fudgy, chewy, and sweet. Each item serves a unique purpose, whether it’s enriching texture, adding moisture, or bringing in bursts of flavor and color.

White granulated sugar: Sweetens both the brownie and cookie dough for that classic dessert sweetness.
Large eggs and egg yolk: Provide structure and moisture, helping your brownies stay fudgy and your cookie dough firm yet tender.
Unsalted butter: Adds richness and a silky texture in both components.
Oil (canola or vegetable): Keeps the brownies extra moist and fudgy without heaviness.
Pure vanilla extract: Enhances overall flavor, offering warm, aromatic notes.
All-purpose flour: The foundation that holds everything together in both the cookie dough and brownie batter.
Unsweetened cocoa powder (Dutch process): Brings deep chocolate intensity to the brownies.
Cornstarch: Helps with tenderness, making the cookies soft and the brownies perfectly fudgy.
Salt: Balances sweetness and highlights the chocolate flavors.
Semi-sweet and milk chocolate chips: Delight in molten pockets of melty chocolate throughout.
Brown sugar: Adds moisture and a subtle caramel-like flavor to the cookies.
Peanut butter (creamy): Infuses the cookie dough with a nutty richness that pairs beautifully with chocolate.
Baking soda and baking powder: Give just the right lift to the cookie dough without compromising fudginess.
Quick oats: Provide delightful chewiness and texture contrast in the cookie layer.
Mini chocolate chips and mini M&M’s: Sprinkle in bursts of chocolate and colorful candy crunch for extra fun and flavor.

How to Make Monster Cookie Fudgy Brownies

Step 1: Prepare the Monster Cookie Dough

Start by combining your dry ingredients for the cookies—flour, cornstarch, baking soda, baking powder, and salt—into one bowl. This will ensure everything is evenly distributed and prevents clumps. Next, cream together the butter, brown sugar, and white sugar until light and fluffy, adding the peanut butter to infuse that classic nutty flavor. Beat in the vanilla and egg until the mixture is smooth and cohesive. Gradually fold the dry ingredients in, then mix in oats, mini M&M’s, and mini chocolate chips. Cover the dough and let it chill for about 40 minutes, allowing all those fantastic flavors to meld.

Step 2: Make the Fudgy Brownie Batter

While your cookie dough chills, preheat your oven to 325°F and prepare a 9×9 inch pan by spraying it with non-stick spray and lining it with parchment paper on the bottom and two sides for easy removal. In a separate bowl, whisk together the flour, cocoa powder, cornstarch, and salt so your dry ingredients are well-mixed. Beat your sugar, eggs, and egg yolk for a full 5 minutes — this step is key to getting a light and fluffy texture. As they beat, melt your butter to add once cool. Gently combine melted butter, oil, and vanilla with the egg mixture, then fold in the dry ingredients carefully to retain as much air as possible. Finally, stir in both kinds of chocolate chips for those irresistible gooey pockets.

Step 3: Bake Brownies and Add Cookie Dough Topping

Pour the brownie batter into your prepared pan, smoothing it into all the corners with a spatula. Bake for 15 minutes, just enough for the brownies to set slightly. Retrieve your chilled cookie dough, break it into small handfuls, and flatten each into a disc shape before pressing them atop the partially baked brownie base. Return the pan to the oven and bake for another 20 minutes. To ensure the cookie dough doesn’t over-brown, loosely tent with foil and bake an additional 5 to 10 minutes until both brownie and cookie dough are set with no noticeable jiggle.

Step 4: Cool and Cut

Allow the Monster Cookie Fudgy Brownies to cool completely at room temperature before slicing. This resting period helps the layers set properly, ensuring clean cuts and perfect texture with every bite.

How to Serve Monster Cookie Fudgy Brownies

Garnishes

Adding a few extra touches when serving these brownies can elevate them even further. A light dusting of powdered sugar or a scoop of vanilla ice cream on the side complements the rich chocolate and the nutty cookie flavors beautifully. For extra color and crunch, sprinkle a handful of mini M&M’s on top just before serving.

Side Dishes

Monster Cookie Fudgy Brownies are dessert stars but pair wonderfully with simple sides like fresh berries or a dollop of whipped cream. A hot cup of coffee or a cold glass of milk also makes the ideal beverage to balance the dense, fudgy richness.

Creative Ways to Present

For birthday parties or celebrations, consider cutting the brownies into bite-sized squares and stacking them into a fun dessert tower. Wrapping individual pieces in colorful parchment paper or clear cellophane tied with ribbon makes them perfect for gifting. You can also serve warm Monster Cookie Fudgy Brownies with a drizzle of caramel or chocolate sauce for a gourmet touch.

Make Ahead and Storage

Storing Leftovers

Store leftover Monster Cookie Fudgy Brownies in an airtight container at room temperature for up to 3 days. This keeps them soft and moist, preserving that perfect texture and flavor.

Freezing

You can freeze these brownies for up to 2 months. Wrap individual pieces tightly in plastic wrap and place them in a freezer-safe container or bag. When you’re ready to enjoy them, thaw overnight in the refrigerator.

Reheating

To warm up chilled Monster Cookie Fudgy Brownies, pop a piece into the microwave for about 15 seconds or heat gently in an oven at 300°F for 5-7 minutes. This brings back that freshly baked, melty softness you crave.

FAQs

Can I use crunchy peanut butter instead of creamy?

Absolutely! Crunchy peanut butter will add extra texture to the cookie dough, making the brownies even more interesting. Just make sure it’s well-mixed in for consistent flavor.

What if I don’t have Dutch process cocoa powder?

You can substitute with natural unsweetened cocoa powder, but expect a slightly different taste and texture. Dutch process is smoother and less acidic, which helps with the fudgy consistency.

Is it okay to use more mini M&M’s or chocolate chips?

Yes! Feel free to increase the quantity or mix in your favorite add-ins like chopped nuts or peanut butter chips to customize your Monster Cookie Fudgy Brownies.

Can I make this recipe gluten-free?

To make it gluten-free, swap the all-purpose flour for a gluten-free blend and ensure your baking powder and other additives are gluten-free too. The texture may vary slightly but it will still be delicious.

How long should I chill the cookie dough before using?

Chilling the cookie dough for at least 40 minutes is ideal for flavor melding and to make it easier to handle when topping the brownies. If short on time, 20 minutes can work but results improve with longer chilling.

Final Thoughts

If you want a dessert that packs a powerful punch of flavor, texture, and color, you have to try making Monster Cookie Fudgy Brownies. They bring together the best aspects of your favorite cookies and brownies into one unforgettable bite. Share them with loved ones or savor a few squares yourself—you’ll quickly find why these brownies become a beloved classic on your dessert rotation.

Monster Cookie Fudgy Brownies Recipe

★★★★★

4.7 from 20 reviews

Author: Olivia
Total Time: 1 hour 10 minutes
Yield: 9 to 12 servings 1x
Diet: Vegetarian

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Description

Monster Cookie Fudgy Brownies combine the rich, fudgy texture of classic brownies with the fun, chewy goodness of monster cookies loaded with oats, peanut butter, chocolate chips, and M&M’s. This decadent dessert features layers of chocolatey brownie topped with chunks of chewy monster cookie dough for an irresistible treat that’s perfect for parties or indulgent snacking.

Instructions

Prepare Monster Cookie Dry Ingredients: In a medium-sized bowl, combine the flour, cornstarch, baking soda, baking powder, and salt. Mix well and set aside.
Beat Butter and Sugars: Using a mixer, beat the room temperature unsalted butter with brown sugar and granulated sugar on medium speed for about 1 minute until light and fluffy.
Add Peanut Butter: Add the creamy peanut butter to the butter-sugar mixture and continue mixing for another minute until fully incorporated.
Incorporate Egg and Vanilla: Add the vanilla extract and the large egg, then mix until combined. Scrape down the sides of the bowl and mix again for an additional 20 seconds to ensure even mixing.
Combine Wet and Dry Ingredients: Slowly add the dry ingredient mixture to the wet ingredients. Mix gently until just combined, then fold in the quick oats, mini M&M’s, and mini chocolate chips. Cover the dough and chill in the refrigerator for 40 minutes.
Preheat Oven and Prep Pan: While the cookie dough chills, preheat your oven to 325°F (165°C). Spray a 9×9 inch baking pan with non-stick baking spray and line the bottom and two sides with parchment paper for easy removal.
Mix Brownie Dry Ingredients: In a medium bowl, whisk together all-purpose flour, unsweetened cocoa powder, cornstarch, and salt. Set aside.
Beat Eggs and Sugar: Using a mixer with a whisk attachment, beat granulated sugar, eggs, and egg yolk for 5 minutes until the mixture is very light and fluffy.
Add Butter, Oil and Vanilla: Melt the butter and let it cool slightly. Add the melted butter, oil, and vanilla extract to the egg mixture, mixing on low speed until combined.
Fold in Dry Ingredients: Remove the mixer and gently fold the dry ingredient mixture into the wet ingredients using a rubber spatula. Be careful to maintain the airiness of the batter. Then fold in the semi-sweet and milk chocolate chips.
Fill Pan with Brownie Batter: Pour the brownie batter into the prepared pan and smooth it evenly into the corners using a rubber spatula.
Initial Brownie Bake: Bake the brownies for 15 minutes. The top should be slightly set but still soft.
Add Monster Cookie Dough Topping: Remove the cookie dough from the fridge. Take small handfuls of dough and flatten them into discs. Distribute these discs evenly over the partially baked brownies until all the dough is used.
Final Bake: Bake the combined brownie and cookie dough layer for 20 minutes. Loosely cover with foil to prevent over-browning. Bake for an additional 5-10 minutes until the cookie topping and brownie are completely set and there is no jiggle in the center.
Cool Completely: Remove from oven and transfer to a cooling rack. Allow the brownies to cool fully to room temperature before slicing to ensure clean cuts.
Storage: Store the Monster Cookie Fudgy Brownies at room temperature in an airtight container for up to 3 days for best texture and flavor.

Notes

For best results, ensure all ingredients are at room temperature, especially eggs and butter when mixing.
Do not overmix brownies batter once dry ingredients are added to keep it fudgy and tender.
If you prefer a nut-free version, substitute the peanut butter with sunflower seed butter.
Use Dutch-processed cocoa powder for a deeper chocolate flavor and richer color.
Chilling the cookie dough before baking helps maintain dough integrity while baking on top of the brownies.
Letting brownies cool completely before cutting prevents them from crumbling or sticking.
You can store these brownies in an airtight container for up to 3 days at room temperature or freeze for up to 1 month.

Prep Time: 25 minutes
Cook Time: 40-45 minutes
Category: Dessert
Method: Baking
Cuisine: American