Melt chocolates and butter in top of a double boiler over simmering water. Remove from hot water and stir in hazelnut spread. Pour mixture onto a small baking sheet and spread 1/2 inch thick. Freeze for one hour or until firm enough to roll into balls. Roll into 1/2 inch balls. Roll balls in crushed candy canes. Place in covered container and store in the freezer. Serve from freezer.