Instructions: Preheat Griddle: Preheat a griddle or non-stick skillet over medium heat.
Mix Dry Ingredients: In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
Combine Wet Ingredients: In another bowl, beat the eggs and then mix in the buttermilk, milk, melted butter, and vanilla extract until well combined.
Cook Pancakes: Grease the preheated griddle with butter or oil. Pour about 1/4 cup of batter onto the griddle for each pancake. Cook until bubbles form on the surface of the pancake and the edges look set, about 2-3 minutes.
Flip Pancakes: Carefully flip the pancakes with a spatula and cook for an additional 1-2 minutes, or until golden brown and cooked through.
Serve: Serve the pancakes warm with additional chocolate chips and maple syrup, if desired.