Combine the dry ingredients in a large bowl and set aside.
In a medium size bowl, whisk together the egg yolks, buttermilk, butter, and vanilla until smooth. Pour into the dry and stir to combine.
In a small bowl, beat the egg whites with a hand-mixer or in a stand-mixer on high until peaks form (about 1-2 minutes). Gently fold these into the batter, careful not to over-mix or deflate the fluffy air pockets.
Scoop spoonfuls of the batter onto the waffle iron and cook until golden brown on each side. Remove and cool slightly before serving.
Serve immediately with toppings and store leftovers in an airtight container in the fridge or freezer.