Prep the oven and pan. Preheat the oven to 375°F (350°F if using a dark cookie sheet). Line the cookie sheet with parchment paper or a silicone baking mat.

Mix the dough. Pour the cake mix into a large bowl. Add the eggs, vegetable oil, lemon zest, and lemon juice, and stir until fully combined. The dough will be thick and sticky.

Chill the dough. Refrigerate the dough for at least 30 minutes. Do not skip this — chilled dough is scoopable and bakes up thick; room-temperature dough spreads flat.

Scoop and roll. Use a small cookie scoop or rounded tablespoon to form the dough into balls. Roll each ball generously in the powdered sugar and place 1 inch apart on the lined cookie sheet.

Bake. Bake for 9–10 minutes, until the bottoms are light brown. The edges do not brown on these, so watch the bottoms and do not overbake — they should look slightly underdone on top when they come out.

Cool. Let the cookies rest on the sheet for a few minutes to set, then transfer to a cooling rack to cool completely.