Rice Krispies treats shape into convincing brain-shaped Halloween desserts with minimal decorating skill. The cereal's bumpy texture does most of the visual work, requiring only a center groove pressed with a butter knife to suggest brain hemispheres.
To make them, melt 4 tablespoons of butter and 2 cups of marshmallows together in a large saucepan over low heat, stirring until smooth. Add a few drops of red food coloring for a pale pink tint, then stir in 4 cups of Rice Krispies cereal until evenly coated. Once cool enough to handle, lightly oil your hands and shape portions into small, slightly flattened ovals. Place on parchment paper to set, then use a butter knife to press a groove lengthwise down the center of each treat. The indentation combined with the cereal's texture creates a brainlike appearance. Optional finishing touches include red sugar sprinkles and red cookie frosting for extra gore.
The treats retain their familiar taste of crisp cereal, butter, and melted marshmallows with a chewy, buttery sweetness. Pink marshmallows work as a substitute if red food coloring is unavailable. Since the treats are meant to look slightly misshapen, they do not need to match.