In a medium bowl, whisk together the flour, cocoa powder, baking powder and salt.
In a large bowl, beat the butter with an electric mixer at medium speed, until light and fluffy. Gradually beat in 2 cups (227g) powdered sugar until well combined. Set aside the remaining 1/2 cup (113g) of powdered sugar in a shallow dish.
Beat in eggs in two separate additions, making sure each one is incorporated before adding the next. Add the extracts and the melted chocolate and beat until well combined. Beat in the flour mixture just until combined.
Cover and refrigerate the dough for at least 2 hours or up to overnight.
Preheat the oven to 350ºF (180ºC). Line two large cookie sheets with parchment paper.
Roll the dough into 15 2-tablespoon size balls, 1 1/4 ounce (35g) each. Roll the dough balls generously in the reserved 1/2 cup of powdered sugar.
Place the dough balls 3 inches apart onto the prepared cookie sheets. Bak until the cookies puff and the tops are set, about 10-12 minutes. Transfer the cookies to a cooking rack to cool.