3/4 c. butter
1 c. sugar
1/2 tsp. vanilla
1 egg
2 c. flour
1/2 tsp. baking soda
1/2 tsp. salt
3/4 c. cocoa
1/4 c. milk
1 tsp. baking powder

Cream butter; add sugar gradually and add vanilla. Beat in egg. Blend in sifted dry ingredients and milk alternately; chill until firm. Shape into 4 rolls, 1-inch in diameter. Wrap in waxed paper. Chill overnight. Cut into 1/8-inch slices. Place on ungreased cookie sheets.

Bake at 325°F for about 8 minutes. Cool. Make Mint Filling.

Mint Filling:

1/4 c. butter
2 1/4 c. powdered sugar
green food coloring
1/8 tsp. peppermint extract
about 1/4 c. milk

Blend all ingredients; beat until smooth. Spread bottom of half of the cookies with 1/2 teaspoon of filling. Place another cookie on top, sandwich fashion.

Makes about 6 dozen.