Preheat your oven to 350°F (175°C) and grease or line a muffin tin with muffin liners.
In a mixing bowl, combine the sourdough starter, granulated sugar, brown sugar, melted butter, eggs, and vanilla extract. Whisk until smooth.
In another bowl, whisk together the all-purpose flour, baking soda, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
Gently fold in the chocolate chips using a spatula or silicone spoon.
Divide the batter evenly among the 12 muffin cups, filling each about two-thirds full.
Bake in the preheated oven for about 20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Let the muffins cool in the tin for 5 minutes before transferring to a wire rack to cool completely.