Preheat oven to 350 degrees.
Combine together sugar, brown sugar, butter, and vanilla. Mix well until all combined.
Whisk in eggs to wet ingredients until it is mixed well.
Add in sourdough starter and mix all together for 2-3 minutes.
While wet ingredients are mixing, in a separate bowl add in flour, baking soda, and salt.
Once the wet ingredients are combined well, slowly add in the flour mixture. Use a spoon to slowly scoop it into the Kitchenaide.
Scrape the sides to make sure all of the dough is mixed well. Add in the chocolate chips and mix together once again.
Spoon out the cookie dough onto the cookie sheet. You can use parchment paper if you prefer, but I am totally fine with the cookie sheet (do not grease!).
Place in the over for 10-12 minutes or until the bottom of the cookie is a nice brown color. The edges will show the brown color also, creating a perfect crunch before your eyes.