In a large bowl, combine the flour, baking powder, baking soda, salt, and sugar. Stir with a whisk to combine and aerate.
2 cups all-purpose flour, 2 teaspoons baking powder, 1 teaspoon baking soda, ½ teaspoon salt, 2 tablespoons sugar
Add the buttermilk and eggs, whisking until combined. The mixture will be lumpy. Allow the mixture to sit for 8 - 10 minutes. It will bubble a bit and thicken.
2 large eggs, 2 cups buttermilk
Heat a large griddle over medium heat. Brush the griddle with melted butter. Spoon about 1/3 of a cup of batter onto the griddle, smoothing it into a circle so it's even. Don't drop batter too close together and don't crowd the griddle.
Flip the pancakes over when the edges look dry and bubbles appear on the surface. Continue cooking until golden brown.
Remove from the griddle and serve with butter and warm maple syrup.