Place 6 (2-oz.) squares melting chocolate in a 2-cup glass measure. Microwave on high 2 minutes, stirring every 30 seconds. Dip sugar cones in the melted chocolate, tilting the measuring glass to coat. Place, pointy end up, on top of large chocolate-covered marshmallow moon pies. Pipe icing around the area where the cone and moon pies meet. Press nonpareils and other candies into icing to create a hatband.