Whisk flour, baking powder, and salt. in a small bowl. Melt one cup of the mint chips over hot water, stirring occasionally.
Beat butter and sugar in a medium bowl until fluffy. Add the melted chips and vanilla. Stir to combine. beat in the eggs then beat in the flour. Stir in the rest of the mint chips. Gather dough into a ball, wrap in plastic , and chill until very firm.
Preheat oven to 350 degrees. Shape the dough into 1 inch balls. Roll thickly in confectioners sugar. Place approximately 2 inches apart on parchment lined cookie sheet.
Bake 10 - 12 minutes until the tops appear cracked. Let sit on cookie sheet for 5 minutes, then move to wire racks to cool completely. Store airtight up to one week.