Preheat oven to 300°F (150°C) and line a baking sheet with parchment paper.
In a clean bowl, beat egg whites and cream of tartar until stiff peaks form (about 3-5 mins).
In another bowl, mix egg yolks, cream cheese, salt, and sweetener (if using) until smooth.
Gently fold the yolk mixture into the whipped egg whites until just combined (do not overmix).
Spoon the mixture into 6 even rounds (~1/2 inch thick) on the baking sheet.
Bake for 18-20 minutes until golden.
Let cool for 5 mins before removing. They will firm up as they cool.
