Preheat your oven to 300°F (150°C). Line a baking sheet with parchment paper or a silicone baking mat.
Separate the egg yolk from the white. Place the egg white in a clean, dry mixing bowl and the yolk in a separate mixing bowl.
Add the Greek yogurt to the bowl with the egg yolks. If desired, add any sweetener, vanilla extract, salt, herbs, or spices for flavoring. Mix until smooth and well combined.
In the bowl with the egg whites, add baking powder and xanthan gum. Using a hand mixer or stand mixer, beat the egg whites on high speed until stiff peaks form. This will take a few minutes. You can tell it is done when you can turn the bowl upside down without the batter spilling.
Gently fold the egg yolk mixture into the beaten egg whites until just combined. Be careful not to deflate the egg whites too much.
Spoon the mixture onto the prepared baking sheet, forming rounds or any desired shapes.
Try to make them all the same size and thickness.
Bake in the preheated oven for about 25-30 minutes, or until the cloud bread is golden brown and set. The tops should be firm to the touch.
Remove from the oven and let cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.
