Monster Brookies
These monster brookies are the perfect Halloween treat! Made with soft monster cookie dough, a layer of Halloween Oreos, and fudgy brownie batter, they’re a delicious combination of peanut butter and chocolate. Topped with Reese’s Pieces, chocolate chips, and flaky sea salt, this really is the best Halloween 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 require a few extra dishes! To create a brownie/monster cookie combo…here’s what needs to happen:
- Brownie Batter – This is up first so it has a chance to firm up in the pan. Using both dark chocolate and cocoa powder, it creates a rich batter that pairs perfectly with the monster cookie dough.
- Halloween Oreos – Why is it that Halloween Oreos taste the absolute best?? I had to highlight them in their own dessert, so we’re adding an entire layer to the middle of these bars.
- Monster Cookie Dough – A combination of butter, peanut butter, oats, chocolate chips, and Reese’s Pieces makes this cookie dough irresistible.
- Assemble – The brownie is spread in the bottom of the pan and topped with the Oreos. Then it’s placed into the refrigerator to firm up while we make the dough. Once prepared, the dough is scooped on top and carefully spread even as we don’t want to disrupt the layers underneath. Top with extra chocolate chips and candies and bake!
Tips for baking soft and fudgy monster brookies
For the best consistency, here are my top baking tips:
- 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.
- 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.
- Peanut Butter – For the monster cookie dough, stick with classic creamy peanut butter like Jif or Skippy.
- 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.
Monster Brookies FAQs
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. Substitute the Oreo center with gluten free Oreos, or leave it out completely.
I wouldn’t recommend this! It will add a completely different texture and consistency.
No, as coconut oil is 100% fat and butter is part fat, part water. If anything you can swap with vegetable oil or any mild oil. If you’re worried about flavor, you can’t taste refined coconut oil one bit.
Sure! Those will work just as good.
Store 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
- Black Velvet Cake
- Frosted Halloween Sugar Cookies
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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Monster Brookies
- Total Time: 2 hours 30 minutes
- Yield: 16 bars
Description
These monster brookies are a delicious combination of soft monster cookie dough and fudgy brownies with a layer of Halloween Oreos in the middle! Loaded with peanut butter candies and chocolate chips, it’s the perfect Halloween dessert.
Ingredients
Brownie Batter
- 1/4 cup (56g) unsalted butter, sliced
- 2 tbsp refined coconut oil
- 1/4 cup (25g) unsweetened cocoa powder
- 1/4 cup (45g) dark chocolate chips
- 1/2 cup (100g) granulated sugar
- 2 tbsp light brown sugar, packed
- 1 large egg + 1 egg yolk
- 1 tsp vanilla extract
- 1/4 tsp kosher salt
- 1/4 cup (32g) all-purpose flour, spooned and leveled
- 14 Halloween Oreos
Monster Cookie Dough
- 1/4 cup (60g) creamy peanut butter
- 3 tbsp refined coconut oil, melted
- 1/2 cup (100g) light brown sugar, packed
- 1 large egg
- 1 tsp vanilla extract
- 1/4 tsp baking powder
- 1/4 tsp kosher salt
- 1/2 cup (50g) quick oats
- 1/2 cup (66g) all-purpose flour, spooned and leveled
- 1/2 cup semisweet chocolate chips (I like to use half regular, half mini) + more for sprinkling
- 1/4 cup (50g) Reese’s Pieces + more for sprinkling
- Flaky sea salt, for topping
Instructions
Brownie Batter
- Preheat the oven to 350F and coat the inside of an 8×8 pan with nonstick spray. Press in a sheet of parchment paper to cover the bottom and two sides, allowing the paper to hang over the sides for easy removal.
- In a medium saucepan over medium heat, melt down the butter and coconut oil. Once melted, whisk in the cocoa powder and bubble for 30 seconds. Remove from heat and stir in the chocolate chips to melt.
- In a large mixing bowl, vigorously whisk together the sugars and eggs until the mixture becomes pale yellow and slightly thickened, about 1 minute.
- Whisk in the salt and vanilla, followed by the chocolate mixture.
- Last, whisk in the flour just until combined.
- Pour the batter into the pan and spread evenly. Lay the Oreo cookies on top in 4 rows of 4, staggering the rows as much as possible and cutting some cookies to fully fit the pan. Just slightly press them into the batter. Place the pan in the refrigerator while we make the monster dough.
Monster Cookie Dough
- In a large bowl, whisk together the peanut butter, coconut oil, and brown sugar until smooth and combined.
- Then whisk in the egg and vanilla, followed by the baking powder and salt.
- Now switch to a rubber spatula and stir in the oats and flour just until combined. It will make a very shiny and smooth dough.
- Last, fold in the chocolate chips and Reese’s Pieces.
- Scoop the dough on top of the Oreo layer, scattering it around the surface. Very carefully spread it out as we do not want to disrupt the layers underneath.
- Once level, top with a handful more of chocolate chips and Reese’s Pieces. Gently press into the surface and bake for 25 to 30 minutes. They’re done when the edges are golden and the surface is no longer glossy.
- Top with flaky sea salt and allow to cool at room temperature for about 20 minutes, then transfer to the refrigerator to cool completely for about an hour or until the pan is no longer warm.
- To release, run a knife along the edges and lift the bars out of the pan. Slice into 16 squares and enjoy!
- Prep Time: 30 minutes
- Cook Time: 30 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
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Meet Jenna
I’m the creator, baker, and photographer behind Butternut Bakery. Here I share desserts for every diet because I believe everyone should have a chance to indulge!
These brookies are amazing!! I took a batch into my office, and they were gone by lunch! Find the Halloween Oreos and make yourself a batch. You will be thrilled when you’re eating the most delicious treat you can imagine. 10 out of 10. 🙂
I made these monster brookies this weekend for my chocolate and peanut butter living adult children. They were a GIANT hit and I will definitely be making them again. I was concerned after reading the reviews that they wouldn’t come out well but no, the instructions were clear and spot-on. Follow them exactly – size of pan etc. The salt on top really nailed it. Thank you for this keeper recipe!
oh my word, these look OUTRAGEOUS and are just begging to be made right now. I live in Asia so i’ll have to use regular Oreos but i know these will be great.
Thanks for sharing, Jenna! I like your website a lot.
These Monster Brookies were so tasty!! I made them over the weekend for a little Halloween get together and they were devoured. I didn’t have Reese’s Pieces on hand, but used some PB M&M’s and they were a great substitute. Also added some Halloween sprinkles in addition to the eye sprinkles. The doughs are sticky so it was a little tricky to get them both together in the pan well without getting black cocoa everywhere, but a good recipe! I did bake closer to 30 minutes and they were set enough to my liking to finish while the pan cooled.
These were a tad over cooked for me. The taste was great, but not as fudgy/chewy as I was hoping for! Next time I’d bake them for 25 minutes instead of 30.
Two part recipe but so worth it!!
These bars are seriously so amazing, go make them rn 🙂 so simple to make! Thank you Jenna!!