Halloween treats have always been my favorite part of the season. I look forward to making spooky snacks as much as I do carving pumpkins with the kids. But that doesn’t mean I want to spend hours in the kitchen when I could be helping with costumes. I prefer treats that look scary but are easy to make.

That’s why these marshmallow Rice Krispies brains are my Halloween hero. They only take about 20 minutes to put together, and the kids think they’re gross enough to be perfect. I use a simple brain mold and pink food coloring to get that creepy look. No fancy decorating skills needed.

Want something that’ll make your guests do a double-take? These are it. They look realistic enough to gross people out, but taste like the Rice Krispies treats everyone loves. Honestly, I make a double batch because they disappear fast once people get brave enough to try one.

Why You’ll Love These Marshmallow Rice Krispies Halloween Brains

Super quick and easy – With just 15-25 minutes from start to finish, you can whip up these spooky treats without spending hours in the kitchen.
Kid-friendly fun – Children will love helping you make these creepy-looking brains, and they’re perfect for Halloween parties or trick-or-treat bags.
Simple ingredients – You probably already have most of these basic pantry staples at home, making this an easy last-minute Halloween treat.
No baking required – Just melt, mix, and shape – no need to turn on the oven or worry about timing anything perfectly.
Spooky presentation – The red food coloring transforms ordinary rice crispy treats into gross-looking brains that are sure to get squeals of delight at any Halloween gathering.

What Kind of Marshmallows Should I Use?

Regular-sized marshmallows work best for this recipe since they melt down smoothly and evenly when heated with the butter. You can use any brand of white marshmallows you have on hand – they all melt pretty much the same way. Mini marshmallows will also work if that’s what you’ve got, but you might need to adjust the melting time slightly since they’ll melt faster than the regular ones. Just avoid using flavored or colored marshmallows since you’ll be adding your own red food coloring to create that spooky brain effect.

Options for Substitutions

This spooky treat is pretty forgiving when it comes to swaps, so here are some options if you’re missing ingredients:

Regular marshmallows: You can use mini marshmallows instead – just use about 5 cups since they pack more densely. Mini marshmallows actually melt a bit more evenly, which can make mixing easier.
Rice Bubbles (Krispies): Any puffed rice cereal will work here. Corn flakes or other crispy cereals can work too, but Rice Krispies really are best for that classic texture and crunch.
Unsalted butter: Salted butter works fine – just skip the added salt in the recipe. You can also use margarine, but butter gives the best flavor.
Red food coloring: Gel food coloring works better than liquid for getting that deep, bloody red color without making the mixture too wet. You can also mix red with a tiny drop of brown for a more realistic brain color.
Salt: The salt really helps balance the sweetness, but if you’re using salted butter, you can skip it entirely.

Watch Out for These Mistakes While Cooking

The biggest mistake when making Rice Krispies treats is overheating the marshmallows, which can make them tough and chewy instead of gooey – keep the heat on low and stir constantly once they start melting.

Another common error is waiting too long to shape your “brains” after mixing in the cereal, since the mixture hardens quickly and becomes difficult to mold – work fast and have your brain mold or your hands ready to go.

Don’t go overboard with the red food coloring either, as too much can make the mixture bitter and overly sticky, so add just a few drops at a time until you get that perfect bloody brain look.

Finally, make sure to butter your hands or use cooking spray when shaping to prevent the sticky mixture from turning into a frustrating mess that sticks to everything.

What to Serve With Marshmallow Rice Krispies Halloween Brains?

These spooky treats are perfect on their own as a Halloween party centerpiece, but they’re even more fun when you create a whole creepy dessert spread! I love setting them out alongside other Halloween goodies like chocolate “dirt” pudding cups with gummy worms, orange-frosted cupcakes, or candy corn mixed with roasted peanuts. For drinks, try serving them with cold milk (maybe tinted green for extra spookiness) or hot chocolate with mini marshmallows floating on top. You can also crumble some of the brains over vanilla ice cream for a crunchy, sweet topping that kids absolutely love.

Storage Instructions

Keep Fresh: These spooky brain treats will stay soft and chewy when stored in an airtight container at room temperature for up to a week. I like to layer them between sheets of parchment paper so they don’t stick together, especially since they can get a bit tacky from the marshmallows.

Make Ahead: Perfect for Halloween party prep! You can make these creepy brains up to 3 days before your party and they’ll still taste fresh. Just keep them covered so they don’t dry out, and the red food coloring will stay nice and bright for that gross-out factor kids love.

Wrap Individual: If you’re giving these out as Halloween treats, wrap each brain individually in plastic wrap or small treat bags. They’ll stay fresh this way and are perfect for trick-or-treaters or school parties without getting sticky fingers everywhere!

Preparation Time	10-15 minutes
Cooking Time	5-10 minutes
Total Time	15-25 minutes
Level of Difficulty	Easy

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

Calories: 1450-1600
Protein: 7-10 g
Fat: 40-48 g
Carbohydrates: 290-320 g

Ingredients

6 cups plain marshmallows
4 cups puffed rice cereal (such as rice krispies)
6 tbsp unsalted butter (equals 85 g)
1/2 tsp salt
Red food coloring

Step 1: Set Up the Bain-Marie

Fill a small pot with 1/2 cup of water and bring it to a boil over medium-high heat.

Place a large heatproof bowl on top of the pot, ensuring that the bowl doesn’t touch the simmering water.

This setup will gently melt your ingredients without burning them.

Step 2: Melt Marshmallows and Butter

6 tbsp unsalted butter (equals 85 g)
6 cups plain marshmallows

Add the unsalted butter and plain marshmallows to the heatproof bowl.

Continually whisk the mixture over the simmering water until it forms a smooth paste, which should take about 2-4 minutes.

Be patient and keep stirring to avoid any lumps or burning.

I like to use a silicone spatula for scraping the sides of the bowl to make sure everything is evenly melted.

Step 3: Add Salt and Food Coloring

1/2 tsp salt
red food coloring

Remove the bowl with the melted marshmallow mixture from the heat, using oven mitts or a tea towel to protect your hands.

Whisk in the salt and add a drop or more of red food coloring to achieve your desired shade.

Mix until the color is evenly distributed.

Step 4: Combine with Puffed Rice Cereal

4 cups puffed rice cereal (such as Rice Krispies)
marshmallow mixture from Step 3

Place the puffed rice cereal in a large mixing bowl.

Pour the warm, colored marshmallow mixture from Step 3 over the cereal.

Use a spatula or wooden spoon to mix thoroughly, making sure all the cereal is well coated with the marshmallow mixture.

Step 5: Shape and Decorate the ‘Brains’

red food coloring (for decoration)
oiled hands (use a few drops of neutral oil, optional)

Oil your hands lightly to prevent sticking, then scoop handfuls of the mixture and shape them into oval ‘brain’ shapes.

Use a butter knife to create a dent in the center of each brain.

Dip a toothpick in red food coloring and draw veins on the tops for a realistic effect.

Store in an airtight container for up to a week.

For extra fun, I sometimes sprinkle a little red sugar on top for more ‘gory’ detail!