Preheat the oven to 300°F.
Put the egg whites and cream of tartar in a big bowl. Using a hand mixer, whip them until they turn solid white and fluffy, just as you would for meringue. This took me 4-5 minutes.
In another bowl, combine the egg yolks, yogurt, Chinese five-spice, and salt. Gently fold in the whipped egg whites. Your cloud bread batter should be an even color.
Line a cookie sheet with parchment paper. Divide your batter into six evenly spaced blobs on the cookie sheet. With the back of a spoon, gently spread each blob into a 4" circle. Try to make the circles a uniform thickness to help ensure even cooking.
Bake your cloud bread for 30 minutes. They should be golden on the outside and not jiggly in the middle when they are finished cooking.
Let your breads cool to room temperature prior to eating.