Preheat a waffle iron according to manufacturer's instructions.
In a large bowl, whisk together the flour, brown sugar, baking powder, cinnamon, ginger, allspice, salt, baking soda, and cloves.
In a medium bowl, beat together the buttermilk, molasses, eggs, butter, and vanilla.
Add the buttermilk mixture to the dry ingredients and whisk by hand or use a hand mixer to combine just until no lumps remain.
Grease the heated iron with butter. Pour in a ladleful of the prepared batter (2 tablespoons for mini waffle iron and about 1/4 cup/60 ml for a standard size). Heat until the waffle is cooked through and starting to turn golden. Transfer to a plate and repeat with remaining batter.
Serve immediately topped with butter, maple syrup, and a sprinkling of powdered sugar if desired.