Line a baking pan that fits in your freezer with parchment paper. Scoop the vanilla ice cream, rounding scoops as much as possible, until you have 4 of each size, and place on the prepared baking pan. Place the pan in the freezer to harden for 15 minutes.
Remove the ice cream from the freezer, and roll in coconut. Return to pan, then return the pan to the freezer. Add orange food coloring to marzipan until carrot color is attained. Shape marzipan into small carrot shapes, using a paring knife to make ridges. Remove 1 small scoop of ice cream at a time from the freezer, and make faces using Sen Sen for eyes and mouth and marzipan carrots for the nose. Return to freezer until ready to serve.
Remove middle-size scoops from the freezer one at a time; place Sen Sen in a row down the front to create buttons. Remove remaining scoops from freezer, and stack to create snowmen, pressing slightly to adhere. Return snowmen to freezer.
Make the top hats by roasting marshmallows on skewers over a gas burner. Alternatively, place marshmallows on a baking sheet under the broiler, and cook until browned, rotating every few seconds. Place the toasted marshmallow on the chocolate wafer, and dust with sifted confectioners' sugar. Place the hat on the snowmen just before serving.