In a bowl, whisk together the buttermilk, butter, sugar, egg, and vanilla until well combined.
1 cup buttermilk or regular milk*, 2 Tablespoons melted unsalted butter, cooled slightly, plus more for greasing, 2 Tablespoons granulated sugar, 1 large egg, 1 teaspoon vanilla
In a separate larger bowl, whisk together the flour, baking powder, salt, and cinnamon.
1 cup all-purpose flour*, 2 teaspoons baking powder, 1/2 teaspoon Morton kosher salt*, 1/4 - 1/2 teaspoon cinnamon, optional
Pour the wet ingredients into the dry ingredients.
Fold gently until just combined. There should be lumps of flour, but no streaks. Let the batter rest for 15 minutes.
Heat a griddle or cast iron skillet over medium low to medium heat. Grease generously by gliding a stick of butter all over the surface.
Pour about ¼ cup of batter onto the skillet. Repeat until the griddle is full. I usually only cook 2-3 pancakes at a time.
Cook the pancakes until bubbles form, and the tops begin to solidify. The bottom should be golden brown.
Flip each pancake and cook for another minute. Repeat with the remaining batter, greasing the skillet between each batch.