1. Combine flour, baking powder, and salt in a small mixing bowl.
2. Beat butter and shortening with an electric mixer a medium speed until fluffy; gradually add sugar. Stir in milk, eggs, and vanilla. Gradually add in flour mixture to cream mixture, mixing well. Add in red food coloring to color the dough, mixing until blended in. shape dough into a ball; cover and chill for at least three hours.
3. Preheat oven to 375°F.
4. Roll dough into 1/4 inch thickness on a lightly floured surface. Cut dough with a 3 inch round cookie cutter; cut circle in half. Place on an ungreased cookie sheet. Press several mini chocolate chips into each cookie. Repeat with remaining dough.
5. Bake in the oven for 8 to 10 minutes. Then let cool.
6. Make frosting: combine powdered sugar and water, mixing until smooth. Add in green food coloring, mixing until blended. Dip round edge of each cookie in green frosting, and place cookie on wax paper until the frosting is firm.