Scary-Cute Monster Mash Halloween Brownies

Disclosure: I may have been on a sugar high when I wrote this post. Halloween Season is officially here! The time of monsters and scary movies, haunted houses and spooks. It is also the time for sticky-sweet treats like these Monster Mash Halloween Brownies. Me and my little ghoul-friend made these over the top Halloween brownies together. Holiday baking is family fun in our kitchen. Magically swirled with bright purple and green buttercream on top of fudgy brownies, this treat has a trick inside.

And a whole lot of sprinkles on the outside. (My little monster likes sprinkles.)

Monster Mash Halloween Brownies


Monster Mash Halloween Brownies

This recipe for Monster Mash Halloween Brownies has a few tricks and a lot of treats.

Trick  – We used a store-bought super fudgy brownie mix. Feel free to make your own homemade brownies. (Check out our OMG Fudgy Brownie recipe.) 

We added a couple of things to our brownie batter to make it extra special. No worries, no toads or eyes of newt or anything like that. Just an extra dose of chocolate covered peanut butter cups. Just mash them right into the brownie batter before baking.


Reese's Peanut Butter cups pressed into a pan of brownie batter


Look at these yummy brownies. It was all I could do to keep from eating them totally naked. The brownies…not me.

The smell of warm chocolate baking with just a hint of peanut butter…it is enough to drive you mad. But my daughter made me wait. She had to get in on these Monster Mash Halloween Brownies.


warm brownies baked with peanut butter cups


Looking for more SUPER-SWEETS? Yep, I have a sweet tooth.

Candy Corn Rice Krispie Treats

Peanut Butter Cup Punch Bowl Cake

Funfetti Cake Batter Waffles

Nutty Peanut Buttery Hot Fudge Sundaes


Or are you in search of Savory Halloween Recipes?

Halloween Chili Cheese RO*TEL Dip

Monster Chorizo Nachos Recipe


As soon as my youngest daughter found out what I was up to, she had to get in on the buttercream action.

Treat  – We made a fast, smooth and creamy homemade Monster Buttercream frosting. (With a hint of cream cheese because my daughter and I are both addicted.)


Young girl stirring purple frosting in a glass bowl


Monster Mash Halloween Brownies are the ultimate recipe to make with your kids. Seriously, does it get any better than mixing up electric-green frosting, playing with colors and all kinds of sprinkles?

Treat – Your little ones will never forget the time spent in the kitchen with you. So don’t worry about the mess, let the sprinkles fly! (Seriously, they fly everywhere. Our dogs got a treat, too, running around the kitchen chasing them down.)


A collage of a young girl enjoying making Halloween treats


Trick – To get your brownies out of the pan with no sticking, spray your baking sheet first. Then, line it with parchment paper. Spray the parchment paper with more butter flavored non stick spray. When the brownies are done, let them cool in the pan for about 15 minutes. Then, grasping the edges of the parchment paper, carefully lift and transfer the brownies to a wire rack.

POOF. Witchcraft.



Halloween brownies swirled with frosting and sprinkles, cooling on a wire rack


Treat – Once the Halloween brownies have cooled completely, let the fun begin. Get crazy and creative. You are only limited by your imagination. Well, your imagination and the selection of Halloween Sprinkles and body parts at your grocery store. Load these brownies up with all the treats.

Don’t hold back.


More fun recipes you should make with the kids:
Almond No Bake Energy Bites
Candy Corn Rice Krispie Treats
Dark Chocolate Frozen Bananas
Blue Bird Easter Egg Chicks


A collage photo showing the different monster faces of the Halloween Brownies


My favorite part? Swirling together the smooth and creamy Purple and Green Buttercream. We used a wooden skewer to create swirls and waves. Just think of all of the fun color combinations you could make. (We use Wilton Icing Gel Colors. It gives the most vibrant colors.)

And eyeball placement. I really loved that part, too.

And making them with my daughter.

Ok, I love everything about this fun recipe for Monster Mash Halloween Brownies!


Rich brownies frosted with bright purple and green buttercream with peanut butter cup centers



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4.28 from 22 votes

Monster Mash Halloween Brownies

Author Buy This Cook That


For the Brownies

  • 1 family size fudgy brownie mix we used Duncan Hines
  • 3 eggs
  • 1/2 cup oil
  • 1/4 cup water
  • 10 - 12 Reese's peanut butter cups

For the Frosting

  • 1 cup butter room temperature
  • 4 oz cream cheese room temperature
  • 4 cups powdered sugar
  • 5 - 6 TB milk or heavy cream
  • 1/2 tsp vanilla
  • Purple & Green Wilton Gel Icing Color
  • Halloween sprinkles
  • Eyeball candy


For the Brownies

  • Preheat oven to temperature on brownie package.
  • Spray an 8x12 pan with butter flavored non stick spray. Line the pan with parchment paper, and spray the parchment lightly.
  • In a bowl, stir together the brownie mix, eggs, oil, and water until just combined. Spread the brownie batter evenly into the bottom of the prepared baking dish. Press the peanut butter cups into the brownie mixture.
  • Bake according to package directions. Cool brownies in the pan for 15 minutes. Carefully grasp the parchment paper and transfer the brownies to a wire rack to cool completely.

For the Frosting

  • Place the powdered sugar in a large bowl. With a hand mixer, beat the sugar on low for a minute to break up the lumps. Add the butter and cream cheese, and beat on low to medium low until the mixture is crumbly.
  • Gradually add the vanilla and milk, beating the frosting until desired consistency.
  • Divide the frosting into two smaller bowls. Tint the bowls with gel icing color to desired shade. Stir well to blend.
  • Frost the brownies with a generous amount of icing, alternating colors. Using a wooden skewer or knife, create a swirl pattern in the frosting.
  • Top with desired sprinkles and candy.
  • Cut into squares and enjoy.




    • Teri says

      Super fun and super crazy. My daughter and I had so much fun making them. The dog was running around on the floor eating up all the sprinkles we dropped.

  1. Tina says

    These look amazing! I want to make them for a party. Can I make them tonight and refrigerate or should I just assemble everything tomorrow?

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