An easy way to make Rice Krispies treats is to melt marshmallows in a pan with butter and mix in dry Kellogg's Rice Krispies cereal. Set the mixture in a baking dish, and cut it into pieces after it cools off.
Gather 3 tablespoons of butter, one 10-ounce package of fresh full-size marshmallows or 4 cups of fresh miniature marshmallows and 6 cups of Kellogg's Rice Krispies cereal. Melt the butter on low heat in a large saucepan. When the butter is fully melted, put the marshmallows in the pan, and stir until they are fully melted. Remove the pan from the heat, and add the Rice Krispies cereal. Stir the mixture well until the cereal is fully coated with the melted marshmallows.
Coat a baking dish with cooking spray or other oil. Transfer the Rice Krispies mixture to the baking dish, and use a greased spatula or wax paper to evenly form the mixture into the dish. Allow the mixture to cool to room temperature, and use a knife to cut it into squares. Serve the treats the same day for best results. Store them for no more than two days in an airtight container at room temperature.