Preheat oven to 425F (220C) and line a 12-count muffin tin with paper liners and set aside.

In a large mixing bowl, combine discard, melted butter, sour cream, egg, and vanilla extract and whisk until smooth and combined.

In a separate medium-sized mixing bowl, whisk together flour, sugar, baking powder, baking soda, and table salt.

Add the dry ingredients to the wet and use a spatula to gently fold together until ingredients are about halfway combined. Add chocolate chips and continue to gently fold together until batter is completely combined (but don’t over-mix, which will make your muffins dense and dry!).

Evenly divide muffin batter into prepared muffin tin (I prefer to divide into only 11 muffin cups for slightly larger muffins). If desired, sprinkle lightly with coarse sugar.

Transfer to center rack of 425F (220C) oven and bake for 8 minutes, then, without opening the oven door, reduce oven temperature to 350F (175C) and continue to bake for 11-12 minutes longer, until a toothpick inserted in the center comes out clean or with a few moist crumbs.

Allow to cool in the muffin tin for 5-7 minutes before carefully removing to a cooling rack to cool further before enjoying (removing them from the muffin tin while warm prevents overcooking and prevents soggy muffin liners).