Give boxed brownie mix a monster makeover with Halloween peanut butter brownies. Easy to customize and fun to decorate, these brownies are a creepy treat.

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A top down view of a 9x13 baking dish filled with freshly decorated Halloween peanut butter brownies, showing off the splotches of orange, black, and white colors, the candy toppings, and the candy eyes.

About Halloween Peanut Butter Brownies

Decorated treats are fun and everyone loves them, but making them for your next event or movie night doesn’t have to mean hours of preparation. Sometimes you can take something that’s already delicious and simply make it better.

Case and point: these festive Halloween brownies.

You can make them with your favorite box of fudge brownie mix as the base, then use all of your creative energy for decorating the top with peanut butter-flavored monster flair!

What’s in these Halloween brownies?

To whip up a batch of monster-peeking brownies, you’ll need the following ingredients:

  • A batch of fudge brownies – This recipe aims to keep things simple and recommends preparing a box of fudge brownies per the package instructions. However, you can also whip up your favorite batch of homemade brownies or buy a batch of brownies that have already been made.
  • Candy melts in orange, black, and white – For creating the colorful ganache on top of the brownies. Feel free to use other Halloween-inspired colors like purple or green.
  • Reese’s Pieces, Reese’s Miniature Peanut Butter Cups, peanut butter chips – For giving these brownies their namesake peanut butter flavor.
  • Orange sanding sugar – Technically optional, but adds more character to the decorations. Feel free to use different types of sprinkles if you’d like.
  • Candy eyes – Because no monster-inspired treat is complete without googly monster eyes.
Two multi-colored Halloween peanut butter brownies in a black and white checkered serving plate, showing off the orange, black, and white candy melts, candy toppings, and candy eyes.

What type of candy melts should you use?

Candy melts (also called melting wafers) are pretty common – you can find them in the baking supply area, and they’re small, flat disks, typically sold by the bag – but I do think there are significant differences in quality depending on the brand of candy melts you buy.

Wilton is by far the most common brand of candy melt, and they are sold in a variety of colors. This makes them a popular pick since you can buy the exact color you need and can get right to crafting your festive treats. Wilton makes things simple and easy.

This recipe recommends using Wilton candy melts (or other brands that come in different colors) because it makes things simpler.

However, I’ve not been impressed with the quality of Wilton candy melts and typically look for alternatives. If given the choice, I would highly recommend picking up Ghirardelli brand candy melts and using oil-based food coloring to get the look that you want. These are my favorite candy melts to work with due to their superior quality and taste. You could also use their white bar chocolate or white chocolate chips.

What other ingredients will you need?

To make things easy, this recipe includes using a box of fudge brownie mix (or whipping up a batch of your favorite homemade brownies).

The brownies will require additional ingredients to make, and because this can vary depending on the brand you buy or the recipe you use, any extras you may need are not included in the recipe below.

So before you begin making these brownies, check the back of the box you buy to ensure you have the additional ingredients on hand. This will typically include baking staples such as:

  • Water or milk (TIP: water can be substituted for milk or chocolate milk for more flavorful brownies.)
  • Eggs
  • Oil
Top down view of a single Halloween brownie on a checkered serving plate, showing off the festive colors and toppings.

Can Halloween brownies be made in advance?

Yes, they totally can!

For best results, I would recommend making them no more than 24 hours in advance. Once prepared, peanut butter brownies can be stored either in a sealed container on the counter or in the refrigerator.

How long are these brownies good for?

Once prepared and stored in a sealed container, these Halloween brownies should last for up to four days.

Can you freeze these brownies?


Once prepared and decorated, these creepy brownies can be stored in a sealed container or freezer bag for up to three months.

Notes & tips for Halloween peanut butter brownies

  • For a deeper peanut butter flavor, add more of the peanut butter chips or Reese’s candy into the brownie batter before baking.
Top down view of a hands holding up a decorated brownie to the camera, breaking it in half to show off the fudge brownie texture inside.

More fun Halloween eats

How to make Halloween brownies

This next part is only a photo tutorial of the recipe steps. If you’re looking for the full recipe measurements and instructions, scroll down to Recipe Details.

Step 1 – Kick things of by preparing your chosen batch of fudge brownies (whether that be from a box mix or homemade.) Allow the brownies to cool completely before decorating.

Step 2 – Prepare the candy melts by putting each color in its own microwave-safe bowl. Add a bit of heavy whipping cream to each bowl, then heat in the microwave until the candy is melted and smooth.

Step 3 – Pour the candy melt ganache on top of the cooled brownies, creating designs and swirls as you see fit.

Step 4 – Top the wet candy with Reese’s Pieces, Reese’s Minis, peanut butter chips, orange sanding sugar, and candy eyes. Be random and have fun with it!

Step 5 – Allow the candy melt ganache to cool and set.

Step 6 – Serve and enjoy!

Recipe Details

A top down view of a 9x13 baking dish filled with freshly decorated Halloween peanut butter brownies, showing off the splotches of orange, black, and white colors, the candy toppings, and the candy eyes.
5 from 1 vote

Halloween Peanut Butter Brownies

15 minutes prep + 25 minutes cook + 1 hour Cooling Time
250 kcal
Yields: 15 brownies
Give boxed brownie mix a monster makeover with Halloween peanut butter brownies. Easy to customize and fun to decorate, these brownies are a creepy treat.



  • Preheat oven to temperature designated on fudge brownie box. Generously spray a 9×13 baking dish with cooking spray, then set aside. NOTE: For easier removal, you can line the baking dish with parchment paper or aluminum foil before spraying with cooking spray.
  • Prepare fudge brownies per package instructions (or prepare a batch of homemade brownies). Once baked, allow brownies to completely cool in the pan, about 30-60 minutes.
    1 box fudge brownies
  • When ready to decorate, prepare your work area. Add each color of candy melt to its own microwave-safe bowl. Also measure out and have handy Reese's Pieces, Reese's Peanut Butter Cup Minis, peanut butter chips, sanding sugar, and candy eyes.
    1/4 cup black candy melts, 1/4 cup orange candy melts, 1/4 cup white candy melts, 1/4 cup Reese’s Pieces, 1/4 cup Reese's miniature peanut butter cups, 1/4 cup peanut butter chips, orange sanding sugar, candy eyes
  • Add 2 tablespoons of heavy whipping cream to each bowl of candy melts. Heat each in the microwave for 30 seconds on 50% power, then stir. Continue to heat for 15-second intervals, mixing in between, until all candy has completely melted and is mixed with the cream.
    6 tablespoons heavy whipping cream
  • Drizzle the candy melt ganache over the cooled brownies, creating patches and swirls as desired. TIP: Use a toothpick to gently drag through the colors to make designs.
  • Scatter Reese's Pieces, Reese's Minis, peanut butter chips, orange sanding sugar, and candy eyes on top of the wet ganache, creating fun and creepy patterns.
  • Allow candy melt ganache to cool and harden completely, about another 20-40 minutes.
  • Serve and enjoy!


Serving: 1brownie | Calories: 250kcal | Carbohydrates: 36g | Protein: 3g | Fat: 11g | Saturated Fat: 5g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Cholesterol: 8mg | Sodium: 135mg | Potassium: 33mg | Fiber: 0.4g | Sugar: 25g | Vitamin A: 91IU | Vitamin C: 0.1mg | Calcium: 10mg | Iron: 1mg

I do my best to provide nutrition information, but please keep in mind that I’m not a certified nutritionist. Any nutritional information discussed or disclosed in this post should only be seen as my best amateur estimates of the correct values.

Author: Chrisy