Preheat the oven to 350ºF (176ºC). Line two baking sheets with parchment paper or a silicone baking mat and set aside.
Add the cake mix, vegetable oil, and eggs to a large mixing bowl. Use a wooden spoon or silicone spatula to combine the ingredients. Stop mixing when there are no visible traces of flour.
Scoop the cookie batter into approximately 1-inch balls. There should be 18-24 cookies, so adjust accordingly. Place the cookie dough balls on the lined sheet pans about 1 inch apart.
Bake for 8-10 minutes in the preheated oven. The cookies should be slightly golden around the edges. Set the sheet pans on cooling racks and let the cookies cool completely.
Notes
Storage: To keep these cookies fresh, store them in an airtight container at room temperature for 3 to 4 days. You can also freeze the cookies for up to two months. To freeze, place the cookies in a single layer on a sheet pan and freeze until firm. Then, transfer the cookies to a freezer-safe container or zipper storage bag and store in the freezer. When you're ready to enjoy them, simply thaw at room temperature for a few hours.