How to Make It
In a large bowl, whisk the flour with the sugar, baking powder, baking soda and salt.
In a medium bowl, whisk the buttermilk with the eggs, vanilla, zest, lemon juice, poppy seeds and the 6 tablespoons of melted butter. Using a wooden spoon, stir the wet ingredients into the dry ingredients just until combined.
Heat a large nonstick skillet or griddle and brush lightly with melted butter. Scoop 1/4-cup mounds of batter into the skillet and spread 3-inch rounds. Cook over moderate heat until the pancakes are golden on the bottom, about 2 minutes. Flip each pancake and cook until fluffy and cooked through, about 2 minutes longer. Transfer the pancakes to plates and serve with maple syrup.