Spray two muffin pans with baking spray. Melt the butter in a large pot or dutch oven over medium-low heat. Add the marshmallows and cook until completely melted and well combined with the butter. Remove the pot from the heat and stir in the vanilla and salt.

Mix in the cereal until evenly coated in the marshmallow mixture. Add a heaping ¼ cup of the rice krispies to 16 muffin cups. Press the treats down in the center using a 1-tablespoon measuring spoon to create the nest shape. Allow the treats to set in the pan for an hour before transferring them to a board or platter to decorate.

Add the coconut to a large resealable (Ziploc) bag. Add 3-4 drops of green food color and vigorously shake the bag to color the coconut. Add around 1 tablespoon to the center of each nest. Top each nest with three mini eggs.