In a large bowl, whisk together flour, brown sugar, baking powder, baking soda, ginger, cinnamon, nutmeg, cloves, and salt.
In a separate bowl, whisk together buttermilk, molasses, eggs, and melted butter until well combined.
Pour wet ingredients into dry ingredients and stir until just combined (small lumps are okay). Cover and refrigerate overnight.
Christmas morning: Remove batter from fridge and give it a gentle stir. Let it sit at room temperature while waffle iron preheats.
Grease waffle iron and cook according to manufacturer's directions, usually about 4-5 minutes per waffle.
Serve warm with maple syrup, whipped cream, or a dusting of powdered sugar.