Lightly spoon flour into measuring cup; level off. In medium bowl, combine all dough ingredients; blend well. Cover with plastic wrap; refrigerate 30 minutes for easier handling.
Heat oven to 350°F. Shape dough into 1-inch balls. Place 2 inches apart on ungreased cookie sheets. With thumb, make imprint in center of each cookie.
Bake at 350°F. for 8 to 10 minutes or until light golden brown. Immediately remove from cookie sheets. Cool completely.
In medium saucepan, combine all filling ingredients except powdered sugar. Cook over low heat until smooth and thickened, stirring constantly. Cool filling slightly. Spoon 1/4 teaspoon filling into center of each cooled cookie; sprinkle with powdered sugar or coconut.