Instructions

  1. Beat butter, sugar, egg yolk, and vanilla in medium bowl until light and fluffy. In another bowl, stir flour, cocoa and salt. Add to butter mixture gradually until blended. Refrigerate dough until firm (about 1 hour).
  2. Heat oven to 350. Lightly grease cookie sheet. Shape dough into 1 inch balls. Beat egg white slightly with fork. Dip each ball into egg white then roll in nuts (I've also done without the egg/nut mixture due to family preference). Place on cookie sheet. Press thumb gently in center of each cookie.
  3. Bake 10-12 minutes or until set. While cooking, prepare filling by combining powdered sugar, 1 T. butter, 2 t. milk, and 1/4 t. vanilla until smooth. Remove wrappers from candies. Remove cookies from cookie sheet to wire rack; cool 5 minutes. Spoon about 1/4 t. filling into each thumbprint. Gently press an unwrapped candy in center of each cookie. Cool completely.