Prepare a baking sheet with a piece of parchment paper.
In a saucepan, combine 2 cups miniature marshmallows and 2 tablespoons butter, melt over low heat and stir until well combined. Remove from heat and add in 1/4 tsp vanilla extract and a few drops of green food coloring. This will be your lightest colored layer, so a nice light shade of green works great.
Combine melted mixture with two cups of puffed rice cereal and stir well.
Pour and press onto baking sheet lined with parchment paper.
Repeat process for following two layers, adding in 1/4 tsp of peppermint extract in place of vanilla extract to your middle layer if desired. For each layer, you will want to create a darker shade of green with your food coloring. Press each layer on top of the previous layer.
Allow to cool. Cut with knife or cookie cutter as desired. Serve and enjoy!