Chocolate Thumbprint Cookies

1/2 c Butter or margarine,

-softened (1 stick) 2/3 c Sugar

1 Egg, separated

2 tb Milk

1 t Vanilla extract

1 c All-purpose flour

1/3 c HERSHEY'S cocoa

1/4 t Salt

1 c Chopped nuts

26 HERSHEY'S KISSES chocolates,

-HERSHEY'S HUGS chocolates, -pecan halves or candied -cherry halves

--VANILLA FILLING

-- 1/2 c Powdered sugar

1 tb Softened butter or margarine

2 t Milk

1/4 t Vanilla extract

In small mixer bowl, beat butter, sugar, egg yolk, milk and vanilla unti light and fluffy. Stir together flour, cocoa and salt; gradually add to butter mixture, beating until blended. Refrigerate dough at least 1 hour or until firm enough to handle. Heat oven to 350'F. Lightly grease cookie sheet. Shape dough into 1" balls. Beat egg white slightly. Dip each ball into egg white; roll in nuts. Place on prepared cookie sheet. Press thumb gently in center of each cookie. Bake 10-12 minutes or until set. Meanwhile, prepare VANILLA FILLING. Remove wrappers from chocolate pieces. Remove cookies from cookie sheet to wire rack; cool 5 minutes. Spoon about 1/4 teaspoon filling into each thumbprint. Gently press chocolate piece in center of each cookie. Cool completely. VANILLA FILLING: In small bowl, combine all ingredients; beat until smooth.