Cook and stir marshmallows, peanut butter, and butter in a saucepan over medium heat until the marshmallows melt completely into the mixture, about 5 minutes.
Put chow mein noodles into a large bowl. Pour marshmallow mixture over the chow mein noodles; stir to coat.
Spray hands with cooking spray or coat with butter so the noodles will not stick to your hands. Scoop noodle mixture from bowl with an ice cream scoop and form into balls, hollowing the center out to create the nest. Arrange 3-4 chocolate eggs into each nest.