Preheat the oven to 350°F. Line a baking sheet with parchment paper and set it aside.
Using a medium-sized mixing bowl and a handheld mixer on medium speed, beat together the cake mix, Cool Whip, egg, and lemon zest until well combined.
Use a 1 tablespoon cookie scoop to scoop out the cookie dough.
Gently roll the dough balls in the powdered sugar.
Place the rolled dough balls 1½ inches apart. Bake for 8-9 minutes, or until the cookies are just beginning to become golden around the edges. Allow the cookies to rest on the baking sheet for 2-3 minutes before transferring to a cooling rack.
To Store: Store any leftover cookies in an airtight container at room temperature for 3 days. You can also place them in an airtight container in the refrigerator for up to 7 days.
To Freeze: You can freeze your baked cookies in an airtight container for up to 2 months.
When rolling the cookie dough in the powdered sugar, try not to gather too much of the sugar on the dough. It can tend to clump and will not produce a pretty crackling surface.
You may need to replace the powdered sugar if it does become clumpy.
Use a silicone baking mat on the cookie sheet for easier cleanup and prevent sticking or burning.