Preheat the oven to 375℉. Line baking sheets with parchment paper.
In a large bowl, use an electric mixer to combine the cake mix, butter, eggs and water to form a soft dough. Shape the dough into 1-inch balls; roll in powdered sugar. Place the cookie dough balls 2-inches apart on the prepared baking sheets.
Bake for 8 to 10 minutes, or until set. Immediately press a thin mint into the center of each cookie. Cool the cookies on the baking sheets for a couple of minutes before moving them to a wire rack to cool.