1 1/2 c. powdered sugar
1 c. softened real butter
2 squares unsweetened chocolate, melted and cooled
1 egg
1 tsp. vanilla
2 1/2 c. flour
1 tsp. baking soda
1 tsp. cream of tartar
1 tsp. salt

In a large mixing bowl, cream butter and powdered sugar.
Add the chocolate, egg and vanilla; mix well.
Combine the dry ingredients, gradually add to creamed mixture, beating well.
Shape dough into a 2-inch diameter roll and wrap in plastic wrap.
Refrigerate for 1 hour or until firm.
Unwrap dough and cut into one-eighth-inch slices.
Place on ungreased cookie sheet.
Bake at 400 degrees for 7 or 8 minutes, or until edges are firm.
Remove to wire racks to cool.
Choose a frosting for your taste.
Store in air-tight container.