This cloud bread is good for sandwiches and it toasts nicely, too.
Preheat oven to 375 degrees Fahrenheit.
Separate the egg whites from the yolks. Add the cream of tartar to the egg whites and beat with a mixer until soft peaks form.
In a food processor, combine the egg yolks, melted butter, almond flour, baking powder, salt, and 1/3 of the beaten egg whites. Mix until combined, but don’t over mix. This will be a lumpy, thick dough until all of the whites are added.
Add the remaining 2/3 of the egg whites and gently process until fully incorporated. Be careful not to over mix as the beaten egg whites give the bread it's volume.
Pour mixture into a buttered loaf pan. Add optional seed toppings, if desired.