Combine the butter, sugar, egg yolks, and vanilla in a large bowl. Beat at medium speed, scraping bowl often, until creamy. Reduce speed to low; add flour. Beat until well mixed. Cover; refrigerate until firm, about an hour.
Heat oven to 375 degrees. Shape dough into 1 inch balls. Place 1 inch apart on an ungreased cookie sheet. Bake for 7-10 minutes. Cool completely.
Combine caramels and whipping cream in a medium microwave-safe bowl. Microwave until melted and smooth, stirring after every minute. Spoon about 1/2 t caramel mixture into the center of each cookie. Top with a pecan half.
Place chocolate chips and shortening in a small microwave safe bowl. Microwave on high for 1 minute; stir. Continue microwaving 30 seconds or until melted; stir until smooth. Drizzle over cooled caramel cookies. Let stand until set, about 2 hours.