In a large saucepan, melt the butter over medium heat until it is fully liquefied.

Once the butter has melted, add in the gelatin-free marshmallows. Stir continuously until marshmallows are completely melted and combined with the butter. Stir in the vanilla extract if using.

Remove the saucepan from heat and quickly add the Rice Krispies. Gently fold the cereal into the melted marshmallow mixture, ensuring all the pieces are evenly coated.

Lightly grease a 9×13-inch pan. Transfer your mixture into the pan and press it down firmly using a spatula or your hands—that’s the key to getting that perfect shape!

Let cool for about 30 minutes. Once set, use a sharp knife to cut into squares or rectangles.

Now that you have created your easy treat, serve them fresh or store them as directed.