Combine butter, sugar, egg yolks and vanilla in bowl. Beat at medium speed until creamy. Add flour; beat at low speed until well mixed. Cover; refrigerate at least 1 hour until firm.
Heat oven to 375°F.
Shape dough into 1-inch balls. Place 1 inch apart onto ungreased cookie sheets. Make indentation in center of each cookie with thumb. (Edges may crack slightly.) Bake 7-10 minutes or until edges begin to brown. Cool completely. Store cookies in a container with a tight-fitting lid for 2-3 days or freeze for up to 2 months.
Combine caramels and whipping cream in bowl, at serving time. Microwave 1 minute; stir. Continue microwaving 1 minute or until melted; stir until smooth. Spoon about 1/2 teaspoon caramel mixture into center of each cookie. Top with pecan half.
Place chocolate chips and shortening in bowl. Microwave 1 minute; stir. Continue microwaving 30 seconds or until melted; stir until smooth. Drizzle over cookies. Let stand 2 hours or until set.
- To store drizzled cookies, place in container with tight-fitting lid. Store at room temperature 1-2 days or freeze for up to 2 months.
- Place cookies on a cooling rack over a piece of waxed paper to catch any extra chocolate drizzle.
- If caramel filling gets too thick, reheat in microwave 10-15 seconds until it becomes spoonable again.