01 - Preheat the oven to 375°F. Line a 12-cup muffin tin with paper liners or lightly grease each cup.
02 - Whisk together the all-purpose flour, granulated sugar, baking powder, baking soda, and salt in a large bowl.
03 - In a separate bowl, whisk the eggs, whole milk, melted butter, and vanilla extract until fully blended.
04 - Pour the wet ingredient mixture into the dry ingredients and stir gently until just combined, keeping the batter slightly lumpy to avoid overmixing.
05 - Fold in the semi-sweet chocolate chips and, if desired, the chopped walnuts or pecans until evenly distributed.
06 - Distribute the batter evenly among the prepared muffin cups, filling each about three-quarters full.
07 - Bake for 18 to 20 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.
08 - Let the muffins cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.