COOKIES:

3/4 c. firmly packed brown sugar
1 c. butter, softened
1 egg yolk
2 c. all-purpose flour

FROSTING:

2 tbsp. butter
1 1/4 c. powdered sugar
1/2 tsp. vanilla
4 to 5 tsp. milk

In large bowl, beat brown sugar and 1 cup butter until light and fluffy. Add egg yolk; blend well. Stir in flour; mix well. Cover with plastic wrap; refrigerate 15 minutes, if necessary, for easier handling.

Heat oven to 325 degrees. Shape dough into 1-inch balls. Place 2 inches apart on ungreased cookie sheets. Flatten to 1 1/2 inch circle with fork dipped in flour. Bake at 325 degrees for 10 to 14 minutes or until light golden brown. Immediately remove from cookie sheets; cool completely.

Heat 2 tablespoons butter in medium saucepan over medium heat until light and golden. Remove from heat. Stir in remaining frosting ingredients, adding enough milk until frosting is of desired spreading consistency; blend until smooth. Spread 1 teaspoon frosting between 2 cooled cookies. Repeat with remaining frosting and cookies. Makes 2 1/2 dozen sandwich cookies.

NOTE: If frosting becomes too stiff as it cools, add enough additional milk until frosting is of desired spreading consistency.