Preheat the oven to 350 degrees. Line a baking sheet with parchment paper.
Add the cake mix, water, and egg to a large bowl and stir until a dough forms.
Use a cookie scoop to drop spoonfuls of dough onto the baking sheet, spacing them 2-3 inches apart.
Bake for 8 minutes, remove from the oven, and transfer the baking sheet to a cooling rack. Allow to cool for 15 minutes before removing the cookies using a cookie spatula.
Notes
Water and egg can be replaced with any flavored soda.
You can add in other ingredients to make it more fun like chocolate chips, peanut butter chips, and nuts.
These cookies spread a lot so try to scoop 1" mounds of batter and space them out on the cookie sheet.
Make sure to use parchment or spray on the cookie sheet as these stick!