1. 2/3 cup butter, softened
2. 1/2 cup sugar
3. 1/2 cup packed brown sugar
4. 1/4 cup whole milk
5. 1 egg
6. 2 cups all-purpose flour
7. 3/4 cup baking cocoa
8. 1 teaspoon baking powder
9. 1/2 teaspoon baking soda
10. 1/4 teaspoon salt
11. FILLING:
12. 2-3/4 cups confectioners’ sugar
13. 1/4 cup half-and-half cream
14. 1/4 teaspoon peppermint extract
15. 1/4 teaspoon salt
16. Green food coloring

Directions

1. In a large bowl, cream butter and sugars until light and fluffy. Beat in milk and egg. Combine the flour, cocoa, baking powder, baking soda and salt; gradually add to creamed mixture and mix well. Cover and refrigerate for 2 hours or until firm.
2. On a lightly floured surface, roll out dough to 1/8-in. thickness. Cut with a 1-1/2-in. cookie cutter and place 1 in. apart on greased baking sheets. Bake at 375° for 5-6 minutes or until edges are lightly browned. Remove to wire racks to cool completely.
3. Combine filling ingredients; spread on bottom of half of the cookies and top with remaining cookies. Yield: about 7-1/2 dozen.