Heat a large saucepan over medium low heat. Add butter and let it melt.

Grease a 13×9 inch pan with non-stick spray. Set aside.

Once the butter has melted add the marshmallows and stir them until they have fully melted. Approximately 5-7 minutes.

When the marshmallows have fully melted add the gel food coloring of your choice. I usually use about 5 drops depending on the color I am going for.

Add the Rice Krispies to the marshmallow mixture and stir together until the marshmallow coats everything.

Lightly coat your hands in a little bit of butter or non-stick spray and then, while the mixture is warm, pour it into the greased pan and use a spatula and your hands to press it down into the pan making a solid layer of rice krispie treats.

Let cool completely and then cut, serve, and decorate with your favorite Halloween decoration. See several Halloween Rice Krispies Treats decoration ideas in the post above.