Begin by assembling a bain marie or water bath in which the cakes will bake.
Place a clean dish cloth or towel (this keeps the ramekins from moving around in the bath) in a large roasting pain or baking dish.
Preheat your oven to 325°F. Butter or spray with cooking spray the bottoms and sides of the ramekins if desired.
Using an electric mixer with the whisk attachment, beat the room temperature egg whites in a medium bowl.
To the sugar mixture, add in the milk, flour, lemon juice, zest and salt beating until smooth.