Preheat oven to 375 degrees F. Line baking sheet with parchment paper or silicone baking mat.
Pour cake mix into a large bowl. Stir in eggs, oil, lemon zest, lemon juice and lemon extract until well blended.
Place confectioner's sugar in a bowl.
Drop heaping tablespoonfuls of dough into balls and roll in confectioner's sugar until lightly coated and place on baking sheet.
Bake for about 10 minutes or until the edges are lightly browned. Cool for 2-3 minutes on the cookie sheet and then transfer to a wire rack to cool completely.
Notes
Store cooled cookies in an airtight container or plastic bag at room temperature for up to 5 days.
Freeze baked and cooled lemon cookies in an airtight, freezer-safe container or plastic bag for up to 1 month. You can also freeze the raw dough already rolled into balls and coated in powdered sugar for up to 3 months.
Reheat baked cookies from frozen by simply allowing them to come to room temperature, or bake the frozen dough for the same cooking temperature and time as before, but with the ability to cook longer if needed (potentially 5-7 extra minutes). Or let the dough thaw in the refrigerator overnight before baking.