Preheat oven to 375°F. Line a 12-cup muffin pan with liners.
Whisk together the freshly milled soft white wheat flour, baking powder, baking soda, and salt.250 g freshly milled soft white wheat flour,7 g baking powder,3 g baking soda,3 g salt.
In a large bowl, whisk together the granulated sugar, brown sugar, eggs, melted butter, buttermilk, sour cream, and vanilla.140 g granulated sugar,25 g light brown sugar,2 large eggs,6 tablespoons butter,1/2 cup full-fat buttermilk,85 g sour cream,8 g vanilla extract.
Add the dry ingredients to the wet ingredients and stir just until combined.
Let the batter rest for 10 minutes to allow the freshly milled flour to hydrate.
Fold 181 g (1 1/4 cups) of the chocolate chips into the batter.255 g semisweet chocolate chips.
Divide the batter evenly among the muffin cups. Sprinkle the remaining 43 g (1/4 cup) chocolate chips evenly over the tops.
Bake for 18 to 22 minutes, or until the tops are set and a toothpick inserted into the muffin portion comes out with a few moist crumbs.
Cool in the pan for 5 minutes, then transfer to a wire rack.
Notes
PRO-TIP: Use full-fat cultured buttermilk for this recipe.Low-fat buttermilk can be thinner and I do NOT recommend homemade buttermilk made wit milk and vinegar or lemon juice. A thinner buttermilk can make the batter too loose and may cause the muffins to sink as they cool. The batter should be thick, not thin and pourable