Chocolate Mint Cookies

Chocolate Mint Cookies or Cocoa Mint Sandwich Cookies (like Oreos)

¾ cup butter or margarine (Blue Bonnet)
1 cup sugar
¾ cup cocoa
½ tsp. vanilla
1 egg, beaten
1 tsp baking powder
½ tsp. baking soda
½ tsp. salt
2 cups flour
¼ cup milk

Cream butter and sugar. Add egg and beat well. Mix dry ingredients thoroughly and add to creamed mixture alternately with the milk. Divide dough into three or four rolls. Wrap rolls in waxed paper and freeze. Cut thin slices (1/8-inch to ¼-inch thick) from the rolls and bake at 325o F. for 8-10 minutes. Cool. Frost with green peppermint frosting. Put together like Oreos.