Preheat your oven to 425°F. Line your muffin tin with silicone liners or paper cups to prevent sticking.

In a large bowl, whisk together the fresh milled soft white wheat flour, cocoa powder, baking soda, baking powder, and salt. This will ensure an even distribution of the leavening agents and cocoa throughout the muffins.

In a separate bowl, combine the sourdough starter, oil, coconut sugar, eggs, buttermilk (or kefir), and vanilla extract. Whisk until smooth and well incorporated.

Gradually fold the wet ingredients into the dry mixture. Stir gently until just combined to avoid overmixing, which can make the muffins dense.

Gently fold in the semi-sweet chocolate chips, distributing them evenly throughout the batter. Fill the muffin liners to the top for bigger muffins, ensuring the batter reaches the top of each liner. For an extra touch, sprinkle a few chocolate chips on top of each muffin before baking.

Bake the muffins at 425°F for the first 5 minutes to help them rise, then reduce the temperature to 350°F and bake for an additional 10-15 minutes. The muffins are ready when a toothpick inserted into the center comes out clean or with just a few moist crumbs.

Let the muffins cool in the tin for 5 minutes, then transfer them to a cooling rack to finish cooling completely. Enjoy your warm, fluffy, and rich chocolate sourdough muffins!