Prepare the Batter: In a large mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
Mix Wet Ingredients: In a separate bowl, whisk together buttermilk, whole milk, egg, melted butter, and vanilla extract.
Combine: Gradually add the wet ingredients to the dry ingredients, stirring until just combined. Avoid overmixing.
Heat the Pan: Preheat a non-stick skillet or griddle over medium heat and lightly grease with butter or oil.
Cook Pancakes: Pour 1/4 cup of batter onto the skillet for each pancake. Cook for 2 minutes until bubbles form on the surface, then flip and cook for another minute until golden brown.
Serve: Remove from heat and serve warm with butter and maple syrup.