Drain the maraschino cherries exceptionally well, pat them dry with paper towels, and chop them finely. Add the cherries, miniature marshmallows, 2 cups coconut, crumbs, sweetened condensed milk, and vanilla to a large bowl, then stir until evenly combined.

Cover the bowl and refrigerate the mixture for 1–2 hours, or until it is firm enough to shape. Scoop about 1 tablespoon of the chilled mixture at a time and roll it into a ball with lightly buttered or dampened hands.

Roll each ball in the additional coconut, gently pressing the coating into the surface. Refrigerate the finished balls until firm, then store them covered in the refrigerator.