Cream together butter and coconut sugar in a stand mixer with the paddle attachment until light and fluffy.
Add in the eggs, sourdough starter, and vanilla extract. Mix until light and fluffy.
Mix together your dry ingredients in a separate bowl: flour, salt, baking powder and baking soda.
Pour the large bowl of dry ingredients slowly into the wet ingredients. For best results, make sure to scrape the sides of the bowl, and mix everything together well
Use your cookie scoop to make the cookie dough balls, and place them onto a parchment-lined baking sheet. They should be spaced 2 inches apart.
Place the sheet into the fridge to chill for at least one hour, or leave them up to three days for longer fermentation
When they are ready to bake, preheat the oven to 375. Bake the cookies for 10-12 minutes. The ideal cookie will be golden brown around the edges.
Remove the cookies from the oven and transfer them to a wire rack right away to cool.
Enjoy!