Preheat the oven to 350°F (175°C).

In a mixing bowl, whisk together the flour, baking soda, and salt.

In another bowl, cream together the softened butter, brown sugar, and granulated sugar until smooth.

Add the egg, sourdough starter, and vanilla extract to the butter mixture and mix until well combined.

Gradually add the dry ingredients to the wet ingredients and mix until just combined.

Fold in the chocolate chips.

Drop spoonfuls of dough onto a baking sheet lined with parchment paper.

Bake in the preheated oven for 10-12 minutes or until the edges are golden brown.

Remove from the oven and let cool on the baking sheet for a few minutes before transferring to a wire rack.