In a small bowl, cream butter and sugar. Beat in egg yolk and vanilla. Combine the flour and salt; gradually add to creamed mixture. Cover and refrigerate for 1 hour or until easy to handle.
In a small bowl, beat egg white. Place coconut in another bowl. Roll dough into 1-in. balls; roll in egg white and coconut. Place 2 in. apart on ungreased baking sheets. Using the end of a wooden spoon handle, make an indentation in the center of each.
Bake at 325° for 19-22 minutes or until lightly browned. Remove to wire racks. Spoon 1 rounded teaspoon of preserves into each warm cookie. Dust with confectioners' sugar. Cool completely.
Every editorial product is independently selected, though we may be compensated or receive an affiliate commission if you buy something through our links. Ratings and prices are accurate and items are in stock as of time of publication.