In a large bowl, whisk the eggs and the vanilla. Add the milk and butter, and whisk to combine.
In a small bowl, mix the flour, sugar, baking powder, and salt. Add these dry ingredients to the wet ingredients bowl, and mix until there's no visible flour left. Add the chocolate chips, and mix to combine.
Cook the waffles:
Preheat your waffle iron and spray (if needed). Pour batter into the hot waffle iron and cook until golden brown. When steam stops coming out of the sides of the waffle maker, it's safe to open the lid to check for doneness. Remove the cooked waffles and repeat with the rest of the batter.
Serve & store:
Serve the waffles warm, topped with syrup or your favorite toppings. Keep them warm on a platter covered with a kitchen towel or in the oven set to 200F on a sheet pan while you cook the rest.
Store leftovers in the fridge in an airtight container for up to 3 days or freeze flat, then transfer to a zip bag, and keep frozen for up to 3 months. Reheat in the microwave for 30 seconds to 1 minute or in the toaster.