Make classic Rice Krispies Treats with butter, marshmallows, and Rice Krispies cereal in 15 minutes. This recipe makes 12 servings. Follow either the stovetop or microwave method to melt, mix, and coat the cereal. Press the mixture into a 13 x 9 x 2-inch pan, cool it, and cut it into squares. Use fresh marshmallows for the best results. You can also use marshmallow creme. Serve the treats the same day for the best texture.