In a mixing bowl, combine the flour, sugar, baking powder, baking soda, and salt. Whisk until well blended.
In another bowl, whisk together the milk, egg, and melted butter until fully combined.
Pour the wet ingredients into the dry ingredients and stir gently. Mix until just combined; do not overmix; it's okay if there are a few lumps.
Preheat the skillet or griddle over medium heat. Lightly grease it with cooking spray or a little butter.
Pour about 1/4 cup of batter onto the skillet for each pancake. Cook until bubbles form on the surface (about 2-3 minutes).
Flip the pancakes and cook for an additional 1-2 minutes, until golden brown and cooked through.
Repeat with the remaining batter, adjusting the heat as necessary.
Serve the pancakes warm with maple syrup, fruit, or your favorite toppings.