1. For tart shells, combine flour, granulated sugar and salt in large bowl. Cut in 3/4 cup cold butter with pastry blender or 2 knives until mixture resembles coarse crumbs. Add water, 1 tablespoon at a time, kneading mixture until dough forms a ball. Shape dough into disc; wrap tightly in plastic wrap. Refrigerate at least 30 minutes.
2. Preheat oven to 375°F. Grease 36 mini (1-3/4-inch) muffin cups. Roll dough on lightly floured surface to 1/8-inch thickness. Cut out circles with 2-1/2-inch round cookie cutter; press rounds into prepared muffin cups. Bake 8 minutes or until very lightly browned. Remove from oven. Reduce oven temperature to 350°F.
3. For filling, combine powdered sugar, 1/2 cup butter and corn syrup in medium saucepan. Cook over medium heat, stirring occasionally, 4 to 5 minutes or until mixture comes to a full boil. Remove from heat; stir in chopped pecans. Spoon into warm baked shells. Top each with pecan half. Bake 5 minutes. Cool completely; remove from pans.