In a large mixing bowl, whisk together the buttermilk, eggs, 6 tablespoons melted unsalted butter, vanilla and brown sugar. Add the flour, baking powder and salt and stir until just combined. It's OK if the batter is a little lumpy. Allow the batter to sit 5-10 minutes.
Preheat your waffle iron.
Cook the waffles according to your waffle iron's directions. I like to slightly undercook my waffles so they are super soft in the center.
In a shallow, low bowl, combine the cinnamon and sugar. Brush each warm waffle generously with the 8 tablespoons melted butter and then dip through the cinnamon sugar. Repeat with the remaining waffles.
Serve your waffles warm topped with butter, whipped cream and drizzled with maple syrup...or your choice of sweet toppings (chocolate sauce, Dulce de Lech, ice cream)! EAT! :)