Preheat your oven to 400°F. Line a 12 count muffin pan with paper liners, and set aside.
In a medium sized bowl, whisk together flour, baking powder, baking soda, and salt to combine. Set aside while you work on the wet ingredients.
In a separate large bowl, combine eggs, granulated sugar, brown sugar, butter, buttermilk, and vanilla. Whisk together until the eggs are broken up and all the ingredients are well combined.
Add your dry ingredients into your wet mix. Gently mix everything together until you no longer see any dry portions of flour (the batter is supposed to be lumpy!). Take care not to over mix! Fold your chocolate chips (or chocolate chunks) into the batter.
Evenly divide your muffin batter into the 12 muffin cups, filling each cup to the top. Bake your muffins for 10 minutes at 400°F. Reduce oven temperature to 375°F and bake the muffins for an additional 8 to 10 minutes, or until a skewer inserted into the center of a muffin comes out clean and the tops are a light golden brown.
Cool slightly before serving. Chocolate chip muffins are best enjoyed fresh and warm!