1 c. butter, softened
2/3 c. sugar
2 egg yolks
1/2 tsp. vanilla extract
2 1/4 cups all purpose flour
1/4 tsp. salt
Chocolate Frosting or Powdered Sugar Glaze

Cream butter; gradually add sugar, beating at medium speed of an electric mixer until light an fluffy. Add egg yolks, one at a time, beating well after each addition. Stir in vanilla. Combine flour and salt; add to creamed mixture, mixing well. Chill dough at least 1 hour.

Shape dough into 1 inch balls; place about 2 inches apart on ungreaed cookie sheets. Press thumb in each cookie leaving an indention. Bake at 300 degrees for 20 to 25 minutes; do not brown. Cool on wire racks. Spoon about 1/2 teaspoon Chocolate Frosting or Powdered Sugar Glaze in each cookie indention. Yield: 3 1/2 dozen.

CHOCOLATE FROSTING:

1 c. sugar
1/4 c. cocoa
1/4 c. milk
1/4 c. butter
1/2 tsp. vanilla extract

Combine first 3 ingredients in a sauce pan. Bring to a boil; boil 1 1/2 to 2 minutes, stirring constantly. Remove from heat; stir in butter and vanilla. Beat until mixture cools slightly. Yield: 1 cup.

POWDERED SUGAR GLAZE:

2 c. sifted powdered sugar
3 to 4 tbsp. milk
1/2 tsp. vanilla extract
Few drops of desired food coloring

Combine all ingredients, and stir until smooth. Yield: 1 cup.

Note: 1 cup strawberry preserves may be substituted for frosting or glaze. If so, bake cookies for 15 minutes. Spoon preserves into indentions, and bake an additional 5 minutes.