Preheat the oven to 350. Spray cookie sheets lightly with nonstick cooking spray; set aside.
Beat cake mix, butter, water, eggs and 1 tsp of peppermint extract in large bowl with electric mixer on medium speed, 1-2 minutes until blended and smooth. Batter will be thick add more water if needed, but sparingly. Stir in chocolate chips.
Drop by rounded tablespoonfuls 2 inches apart onto prepared cookie sheets. Bake 12 minutes or until edges are set and centers are no longer shiny. Cool 5 minutes on cookie sheet. Remove to wire rack; Cool completely.
Stir remaining tsp of peppermint extract into vanilla frosting. Spread on cooled cookies and and decorate with sugar sprinkles.