Spooky Monster Brookies

These monster brookies are the perfect Halloween treat! Made with soft monster cookie dough and fudgy brownie batter, they’re a delicious combination of peanut butter and chocolate. Along with peanut butter candies and chocolate chips, the top is adorned with little candy eyes to create a spooky (or maybe just adorable) dessert.

What is a brookie?

As the name suggests, brookies are a combination of brownies and cookies! Traditionally it’s chocolate chip cookie dough and brownie batter baked together, but this is a fun twist on the classic recipe in order to make it a fun Halloween treat.

How to make monster brookies

Every step of this recipe is very simple, but it does requirer a few extra dishes! To create a brownie/monster cookie combo…here’s what needs to happen:

1. Brownie Batter – This is up first and it’s mixed in one bowl. Using both dark chocolate and cocoa powder, it creates a rich batter that pairs perfectly with the monster cookie dough. If you’re short on mixing bowls, scoop the batter into a smaller bowl and clean out the mixing bowl to prep it for the cookie dough.
2. Monster Cookie Dough – This requires a couple extra steps compared to the brownie batter, but it’s still very easy to make! A combination of butter, peanut butter, oats, chocolate chips, and Reese’s pieces makes this cookie dough irresistible.
3. Assemble – When both the batter and dough are prepped, spoon random dollops of each into a baking pan. Make sure to get an even scatter of each so that every bar has both brownie and monster cookie. Spread both even (without mixing them together) and bake!

Tips for baking soft and fudgy monster brookies

For the best consistency, here are my top baking tips:

1. Flour – I say this in every post, and for good reason. It’s the number one reason why most recipes fail. If there’s too much flour, these bars will turn dry. If possible, measure the flour (and cocoa) with a food scale. Otherwise, to ensure the exact amount, gently spoon the flour into the measuring cup and level it off with a flat edge. If scooped directly into the flour container, the flour becomes packed down into the cup which could leave you with 1/4 cup or more of added flour.
2. Eggs & Sugar – For the brownies, REALLY mix together the eggs and sugar. It’s important to whip the mixture until it’s pale and almost creamy. During this stage, the sugar dissolves while also whipping air into the egg. This combination of creations creates an incredibly smooth and fudgy brownie consistency.
3. Peanut Butter – For the monster cookie dough, stick with classic creamy peanut butter like Jif or Skippy.
4. Mixing – For both batter and dough, carefully mix once the dry ingredients are added to the wet ingredients. Over mixing can lead to a tough cookie or brownie so gentle mixing is key.
5. Topping – In order for the candy eyes to stick, melted chocolate is needed. Make sure to scatter a good amount of chocolate chips on top before baking. Then when it’s fresh from the oven, the eyes will easily stick right on top.

Alternative cookie bar decorations

For a “spooky” theme, I opted to top these monster brookies with candy eyes. They’re very easy to find, especially around Halloween. If you prefer a different look, here are a few different decorating options:

1. Classic – For any other time of year, simply swap the Reese’s pieces with regular M&Ms (I like a combo of both regular size and mini size) and leave off the eyes.
2. Level Up – Use the same exact recipe, but add some orange food coloring to the monster cookie dough! This will create a great black and orange combo.
3. Halloween Colorful – Swap the Reese’s pieces with the M&M ghouls mix (green, purple, and orange). You can also mix in a similar color blend of Halloween jimmie sprinkles into the monster cookie dough and/or sprinkle some on top.
4. Strictly Fall – Swap the candy eyes with candy corn or pumpkins plus salted peanuts to balance out the sweetness.
5. Christmas – If you want to jump to the next holiday, swap the Reese’s pieces with Christmas colored M&Ms and swap the eyes for some red and green sprinkles.

When is the best time to serve brookie bars?

The best is when they’re just BARELY warm. At this temperature, they hold their shape while still remaining soft and tender.

Allow the bars to cool at room temperature for about 45 minutes, then they’ll be perfect for slicing and serving.

Can this recipe be made gluten free?

I haven’t tested it myself, but try swapping the all purpose flour with a cup for cup gluten free baking flour. I think it could work well! Also make sure to use certified gluten free oats if you are celiac. Reese’s pieces are also gluten free, but I would beware of the candy eyes as the label is not very clear on whether or not they’re gluten free.

How to best store monster brookies

Storre the bars in an air tight container at room temperature. They’ll keep for about 4 days.

For more halloween dessert recipes, check out my:

• Sorting Hat Butterbeer Cupcakes
• Mini Pumpkin Hand Pies
• Halloween Candy Cookie Bars
• Cookies & Cream Brownie Pumpkin Cheesecake Bars

Make sure to tag me @butternutbakery on Instagram and leave a review below if you make these monster brookies. To pin this recipe and save it for later, you can use the button on the recipe card, the buttons above or below this post, or on any of the photos above. Happy baking!

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