In the bowl of a stand mixer, combine the cake mix, frozen lemonade concentrate, water, sour cream, eggs, and zest of 1 lemon. Beat together, on medium speed, for 2 minutes.
15.25 ounces white cake mix, ¼ cup frozen lemonade concentrate, ¾ cup water, ⅓ cup sour cream, 1 medium lemon, 3 large eggs