Combine the granulated sugar, eggs, melted chocolate, shortening, baking powder, and peppermint extract in a large bowl. Beat with an electric mixer on medium speed until combined, scraping sides of bowl occasionally. Gradually beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour.
Cover and chill for 2 to 24 hours or until dough is easy to handle.
Preheat oven to 375 degrees F. Line cookie sheets with Reynolds(R) Parchment Paper; set aside. Shape dough into 1-inch balls. Roll balls in powdered sugar and place 2 inches apart on prepared cookie sheets.
Bake about 9 minutes or until edges are just set. Transfer the cookies on the parchment paper to a wire rack; cool completely.
