In a large bowl, whisk melted butter, brown sugar, eggs, vanilla, and buttermilk until smooth. In a separate medium bowl, combine flour, baking powder, baking soda, and salt. Fold flour mixture into liquid until batter is just combined.
In a small bowl, combine granulated sugar and cinnamon. Set aside for a moment.
Preheat a large skillet or griddle over medium heat and lightly brush with butter. Working in batches, drop pancake batter by heaping 1/4 cupfuls onto hot skillet. Sprinkle a layer of cinnamon sugar the raw side of pancake and allow to cook 2-3 minutes on each side, flipping once until pancakes are golden brown. Repeat cooking method with remaining batter, adding more butter to skillet as needed.
Serve pancakes warm with butter and maple syrup. Enjoy!