Beat butter at medium speed with an electric mixer until creamy. Gradually add powdered sugar and vanilla, beating well. Add flour and salt, mixing until well combined. Cover and chill 30 minutes.
Roll dough into 48 (3/4-inch) balls, and place on parchment paper-lined baking sheets. Press thumb in center of each cookie to make an indention.
Bake at 350° for 10 to 12 minutes or until lightly browned on edges. Cool completely on wire racks.
Dollop cream cheese frosting into cookie indentions; top each cookie with a gumdrop. Sprinkle with edible glitter, and dust with powdered sugar.
Note: Edible glitter can be found at crafts stores.