1
Add butter to a pot and melt over medium heat.
2
Once the butter is melted, add mini marshmallows. Continue to stir and cook over medium heat.
3
When the marshmallows are fully melted and incorporated into the butter, remove the pot from the heat. Stir in the vanilla extract.
4
Stir in the rice krispies cereal.
5
Stir until all of the cereal is well coated in the melted marshmallow mixture.
6
Line an 8×8 dish with waxed paper or foil coated lightly with oil. Press the rice krispie mixture into the dish using a lightly oiled spatula. Avoid packing it down too firmly.
6
Allow to cool at room temperature or in the refrigerator until firm, then slice into nine pieces.