Cook microwave popcorn according to package directions.
Transfer to large bowl and remove all unpopped kernels.
Put butter in a microwave safe bowl, microwave on high for 30-60 seconds until melted. Add marshmallows. Cook an additional 90 seconds or until puffy. Stir in vanilla.
Pour marshmallow mixture over the popcorn. Stir until well coated.
Spray hands generously with cooking spray. Form into popcorn balls using the Good Cook popcorn baller or by hand.
Dip each ball into sprinkles.
Fill each ice cream cone with candy, and place popcorn ball onto top of cone, pressing gently but firmly. Be careful not to push too hard, or you will break the cone.