Separate egg whites and yolks.
In a bowl, beat cream cheese until smooth. Beat in egg yolks and cheddar cheese until well combined; set aside.
In another bowl, beat egg whites and cream of tartar until stiff peaks. Fold half of the egg whites into cheese mixture to lighten. Fold in remaining egg whites.
Using a small ladle, pour mixture into 6 large or 8 smaller circles onto parchment paper lined baking sheet leaving about 2 inches (5 cm) in between each. Sprinkle top of each with everything bagel seasoning.
Bake in 300 F (160 C) oven for about 20 minutes or until golden and firm. Let cool slightly before removing from baking sheet to serve.
Note: Once completely cooled, layer in between parchment paper and refrigerate or freeze until ready to use. Thaw in refrigerator if frozen. Lightly toast on lowest setting of toaster to reheat. Reheating in the microwave will give you a very soft cheese bread.