Line two baking sheets with parchment paper or silicone baking mats. Set aside.
In a large bowl, beat together the cake mix, eggs, and vegetable oil until smooth and completely combined, about 2 minutes.
Add the chocolate chips to the cookie batter to personal preferences.
Use a 1 1/2 Tablespoon cookie scoop to portion out the cookie batter at least 3" apart on the prepared cookie sheets.
Bake for 10-12 minutes until lightly golden and spread out.
Allow the cookies to cool for 5 minutes on the baking sheet before attempting to remove to a cooling rack or serve.
Notes
Don't Overmix the Batter: Mix just until everything is combined and smooth. Overmixing develops too much gluten and can lead to flat, tough cookies instead of soft, chewy ones.
Space Them Properly: These cookies spread significantly during baking, so give them plenty of room. If you crowd the pan, they'll bake into each other and you'll end up with one giant cookie sheet.
Watch the Baking Time: Every oven is different, so start checking at 10 minutes. The cookies are done when the edges are set but the centers still look slightly soft. They'll firm up as they cool.
Use Room Temperature Eggs: Cold eggs from the fridge can make the batter harder to mix smoothly. Let your eggs sit out for about 30 minutes before baking, or place them in warm water for 5 minutes.
Measure the Oil Accurately: Too much oil makes the cookies greasy and flat, while too little makes them dry. Use a liquid measuring cup and check at eye level for the most accurate measurement.
Don't Skip the Cooling Time: Letting the cookies cool on the baking sheet is essential. They're too soft to move right away and need those 5 minutes to set up properly.