First, preheat the oven to 425 degrees F, then line a 12-well muffin pan with muffin liners.
Sift the flour, cocoa powder, baking powder and salt until combined. Set aside.
160 grams all-purpose flour, 60 grams unsweetened cocoa powder, 8 grams baking powder, 3 grams salt
In another bowl, whisk together the sugars, melted butter, eggs, milk, sour cream, sourdough discard, and vanilla extract until smooth.
150 grams granulated sugar, 50 grams light brown sugar, 113 grams unsalted butter, melted, 110 grams eggs, 120 grams sour cream, room temperature, 120 grams sourdough discard, 8 grams vanilla extract, 60 grams whole milk
Pour the wet ingredients into the dry mixture and mix until there are just a few streaks of flour left. With a rubber spatula, fold the chocolate chips into the thick muffin batter. Leave the batter to rest for 15 minutes.
170 grams semi-sweet chocolate chips
Long Ferment: To long ferment this muffin batter, cover and place in the fridge to cold-ferment overnight, then bake as normal the following morning.
Once the batter has rested, scoop about 100 grams (5 Tablespoons) into each muffin liner. The muffin tins will be full. This creates the most perfect muffin tops. Top each with more chocolate chips, if desired.
Bake for 7 minutes, then reduce the temperature to 350 degrees F and continue to bake for 11-13 minutes or until a toothpick placed in the center comes out clean.
Keep the muffins in the muffin tin for 5 minutes before removing to cool on a wire rack. Enjoy!