Prepare the Dry Ingredients: In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
Combine Wet Ingredients: In another bowl, whisk together the buttermilk, milk, egg, melted butter, and vanilla extract (if using).
Mix Wet and Dry Ingredients: Pour the wet ingredients into the dry ingredients and gently stir until just combined. Do not overmix; it's okay if there are a few lumps.
Preheat the Pan: Heat a non-stick skillet or griddle over medium-high heat. Add a small amount of butter or oil to coat the surface.
Cook the Pancakes: Pour 1/4 cup of the pancake batter onto the hot skillet for each pancake. Cook until you see bubbles forming on the surface, and the edges start to look set, about 2-3 minutes.
Flip and Cook Again: Carefully flip the pancakes with a spatula and cook for an additional 2-3 minutes, or until they are golden brown and cooked through.
Serve Warm: