Melt the Marshmallows

1. Prepare Your Pan: Start by greasing a 9×13-inch baking pan with butter or non-stick spray. This will ensure the treats come out easily once they’re set.
2. Melt the Butter: In a large pot over low heat, melt the butter. Stir it occasionally to make sure it doesn’t burn.
3. Add the Marshmallows: Once the butter is fully melted, add the mini marshmallows to the pot. Stir constantly until they’re completely melted and smooth.
4. Add Vanilla: Once the marshmallows are melted, add the vanilla extract (if using) and stir it in.

Combine with Rice Krispies

1. Mix with Cereal: Pour in the Rice Krispies cereal and stir gently but thoroughly to coat all of the cereal with the melted marshmallow mixture. Be careful not to crush the cereal.
2. Transfer to Pan: Immediately pour the mixture into your prepared baking pan, and use a spatula or spoon to gently press the mixture down into the pan. Make sure it’s even and smooth, but avoid pressing too hard, as that can make the treats too dense.

Chill and Set

1. Cool: Let the Rice Krispie treats sit at room temperature for about 30 minutes to set. You can also pop them in the fridge for quicker results.
2. Cut: Once the treats are cool and set, cut them into squares. Use a sharp knife to get clean edges.