Brush a thin layer of the softened butter over a parchment-paper-lined 9-inch by 13-inch pan.
Pour marshmallows, butter, and red candy melts into a microwave-safe bowl.
Heat on high power for three 30 second bursts of power, stirring after each until melted.
Stir in some red food coloring so that the marshmallow mixture becomes vibrantly red.
Stir in the cereal.
Pour marshmallows, butter, and green candy melts into a microwave-safe bowl.
Heat on high power for three 30 second bursts of power, stirring after each until melted.
Stir in some green food coloring so that the marshmallows mixture becomes vibrantly green.
Use greased hands to press the green cereal into an even layer over top of the red cereal layer.
Turn the pan upside down and allow the cereal treat to fall out onto a silicone mat or a buttered piece of parchment paper.
Starting at one of the shorter ends, roll the cereal treat up into a log, pinching together any gaps in the cereal treat.
Freeze for 5-10 minutes just until the cereal treat has cooled.
Store in an airtight container set at room temperature for up to 10 days.
Red and Green Rice Krispies® Treat Christmas Pinwheels https://hungryhappenings.com/red-and-green-rice-krispies-treat-christmas-pinwheels/