Preheat the oven to 300°F. Line a baking sheet with parchment paper.
Separate the eggs, placing the whites in a medium bowl and the yolks in a separate small bowl.
Add the cream of tartar to the egg whites and beat with an electric mixer on medium until stiff peaks form, 1 to 2 minutes. Set aside.
In a large bowl, beat the cream cheese with an electric mixer on medium-high until smooth, about 1 minute. Add the egg yolks and salt and beat until well combined, about 1 minute. Using a spatula, fold the meringue into the cream cheese mixture until just incorporated.
Divide the mixture into 6 mounds (about ⅓ cup each) on the prepared baking sheet, spacing them at least 3 inches apart. Spread each mound into a 3½-inch circle.
Bake for 25 to 30 minutes or until golden brown. Let the bread cool completely on the baking sheet, about 15 minutes, before serving.
Notes
Make sure there is no egg yolk whatsoever in the egg whites. The egg whites will not whip up into a meringue if there are any remnants of fat from the yolks.
For a stable meringue: Egg whites whip better when they're at room temperature. Beat the egg whites at medium speed rather than a higher speed. While it takes a little longer to form stiff peaks, the lower speed creates a more stable meringue.
Flavor options: Think of cloud bread as a blank canvas that you can season or flavor any way you like. You can fold in a teaspoon of savory dried herbs and spices like garlic powder, Italian herbs, smoked paprika, or your favorite seasoning blend to create a flavored bread. You can also add 1-2 tablespoons of finely chopped fresh herbs, or grates parmesan cheese. For a sweeter take, add a tablespoon of sugar and a few sprinkles of your favorite baking spices. Or, sprinkle the tops of the hot bread rounds right out of the oven lightly with cinnamon sugar.