Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy.
Add the active sourdough starter, egg, and vanilla extract to the mixture, and whisk until well combined.
In a separate bowl, mix together the all-purpose flour, baking soda, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. If using, fold in the chocolate chips.
Scoop tablespoon-sized portions of the cookie dough onto the prepared baking sheet, leaving space between each cookie to allow for spreading.
Bake in the preheated oven for 10 to 12 minutes or until the edges are lightly golden.
Remove from the oven and let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.