Introduction

These Monster Cookie Fudgy Brownies combine the rich, deep chocolate flavor of fudgy brownies with the colorful, chewy texture of monster cookie dough. Perfect for those who love a mix of chocolate, peanut butter, oats, and candy in one irresistible treat.

The image shows a stack of thick, square dessert bars on a white marbled surface. Each bar has two clear layers: a dark, fudgy chocolate base that looks moist and dense, and a lighter, crumbly top layer with colorful candy-coated chocolates embedded throughout. The candies are red, green, yellow, and blue, adding bright spots of color to the mostly brown and golden bars. Some bars are placed horizontally, while others rest on their sides, revealing the layers and texture inside. The background is softly blurred with a neutral, light tone. photo taken with an iphone --ar 4:5 --v 7

Ingredients

For the Brownies:

1 1/3 cups white granulated sugar
2 large eggs
1 egg yolk
5 tablespoons unsalted butter
1/3 cup canola or vegetable oil
1 teaspoon pure vanilla extract
1/2 cup all-purpose flour
3/4 cup unsweetened Dutch process cocoa powder
1 tablespoon cornstarch
1/4 teaspoon salt
1/2 cup semi-sweet chocolate chips
1/2 cup milk chocolate chips

For the Monster Cookie Dough:

1/2 cup all-purpose flour
1 teaspoon cornstarch
1/2 teaspoon baking soda
1/8 teaspoon baking powder
1/4 teaspoon salt
1/4 cup unsalted butter, room temperature
1/3 cup packed light or dark brown sugar
1/8 cup white granulated sugar
1/4 cup creamy peanut butter
1 teaspoon pure vanilla extract
1 large egg, room temperature
1/2 cup quick oats
1/2 cup mini chocolate chips
1/2 cup mini M&M’s

Instructions

Step 1: Prepare the monster cookie dough by mixing the flour, cornstarch, baking soda, baking powder, and salt in a medium bowl.
Step 2: In a mixer, beat the butter, brown sugar, and granulated sugar on medium speed for 1 minute until light and fluffy. Add peanut butter and mix for another minute.
Step 3: Add the vanilla extract and egg to the mixture. Mix until combined, scrape the sides, and mix again for 20 seconds.
Step 4: Gradually add the dry ingredients to the wet ingredients. Once combined, fold in the oats, M&M’s, and mini chocolate chips. Cover and chill in the refrigerator for 40 minutes.
Step 5: When the cookie dough is nearly done chilling, preheat your oven to 325°F (163°C). Grease a 9×9 inch baking pan with non-stick spray and line the bottom and two sides with parchment paper for easy removal.
Step 6: In a medium bowl, whisk together the flour, cocoa powder, cornstarch, and salt for the brownie batter.
Step 7: Using a mixer with a whisk attachment, beat the sugar, eggs, and egg yolk on high speed for 5 minutes until very light and fluffy. Meanwhile, melt the butter and let it cool slightly.
Step 8: Add the melted butter, oil, and vanilla extract to the egg mixture and mix on low until combined. Gently fold in the dry ingredients using a rubber spatula, being careful not to deflate the batter.
Step 9: Fold in both types of chocolate chips. Pour the brownie batter into the prepared pan and smooth it out evenly.
Step 10: Bake for 15 minutes until the top is slightly set but not fully baked.
Step 11: Remove the cookie dough from the fridge. Take small handfuls and flatten them into discs. Place these cookie dough discs evenly over the partially baked brownie layer.
Step 12: Return the pan to the oven and bake for another 20 minutes. Then tent loosely with foil and bake an additional 5–10 minutes until the brownie and cookie dough are fully set and no longer jiggle.
Step 13: Cool the brownies completely on a wire rack before cutting. Store at room temperature.

Tips & Variations

For high altitude baking, add 1/2 tablespoon of flour to both the brownie and cookie dough mixtures to improve texture.
Use a kitchen scale or spoon and level your flour to avoid dense brownies caused by too much flour.
Substitute peanut butter with cookie butter or sunbutter to accommodate nut allergies.
If using an 8×8 inch pan, expect thicker brownies and possibly longer baking time.

Storage

Store the brownies at room temperature in an airtight container for up to 3 days. They can also be refrigerated for up to a week; allow them to come to room temperature before serving to restore their fudgy texture. Reheat gently in the microwave if desired.

How to Serve

A close-up view of a stack of thick square dessert bars placed on white parchment paper over a white marbled surface. Each bar has two layers: the bottom layer is dense and dark brown, resembling rich chocolate, and the top layer is lighter golden brown with a crumbly texture, studded with colorful candy-coated chocolate pieces in red, yellow, green, blue, and orange scattered throughout. The bars are stacked unevenly, showing gooey chocolate chunks melting inside the bars, with the colors and textures clearly visible. The background is softly blurred with a neutral tone and a hint of natural light coming from the side. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use a different size pan for baking?

Yes, you can use an 8×8 inch pan, but the brownies will be thicker and may require a longer baking time. For a 9×13 inch pan, double the recipe for best results.

Is it necessary to chill the cookie dough?

Chilling the cookie dough helps it firm up, making it easier to shape and bake on top of the brownies without melting too quickly. It also improves the flavor and texture.