In a large bowl, cream butter and sugar until light and fluffy. Beat in vanilla. Combine flour and salt; gradually add to creamed mixture and mix well. Stir in coconut and pecans. Divide dough into two portions. Cover and refrigerate for 30 minutes or until easy to handle.
On a floured surface, roll each portion to 1/8-in. thickness. Cut with a 1-in round cookie cutter. Place 1 in. apart on greased baking sheets. Bake at 350° for 10-12 minutes or until lightly browned. Cool for 1 minute before removing from pans to wire racks to cool completely.
Meanwhile, for filling, in a large heavy saucepan, bring sugar and water to a boil. Add corn syrup; cook until syrup turns golden, about 5 minutes (do not stir). Gradually stir in cream and butter.
Spread a scant 1/2 teaspoon caramel filling on the bottoms of half of the cookies; top with remaining cookies. Let stand for 2 hours or until set. Yield: 4 dozen.