For the waffles:

1. In a large bowl, rub together lemon zest and sugar until fragrant and the sugar has absorbed some of the lemon oil. Stir in flour, salt, baking soda, and baking powder. In a small bowl or liquid measuring cup, whisk together buttermilk, butter, vanilla, and egg yolks. Stir buttermilk mixture into the dry mixture until mostly smooth (a few lumps are fine).
2. In a large glass or metal bowl, whip egg whites until you’ve reached stiff peaks (this is easiest with a hand mixer). You’ll know you’ve reached stiff peaks when you can fluff up the mixture with a spatula or the beaters and the peak will maintain its shape. Gently fold whipped egg whites into the waffle batter.
3. Cook waffles in waffle iron according to manufacturer’s directions.

For the whipped cream cheese topping:

1. While the cream cheese is still cold and in the wrapper, manipulate it with your hands just until it’s pliable. Place cream cheese in a large bowl with sugar, lemon zest, lemon juice, and vanilla. Whip until very smooth and sugar is dissolved (when you rub it between your fingers, you should not feel any sugar granules). Pour in cream and continue to whip until mixture resembles thick, softly-whipped cream cheese. Refrigerate about 30 minutes before serving.

To serve:

1. Dollop cream cheese topping on top of waffles, or create a stuffed French toast effect by sandwiching the filling between two waffles and garnish with powdered sugar.