Preheat oven to 325 degrees F. Grease a small bread pan with avocado oil spray and set aside. Separate the eggs, and whip the whites with the cream of tartar for a few minutes until VERY stiff.
Very slowly add in egg white protein. Fold the reserved yolks and seasonings to the whipped whites.
Spoon the mixture into the pan and smooth the top with a spatula. Bake at 325 degrees F for 30 minutes until lightly browned. Cool completely before cutting. Once cool, cut into 12 pieces. Place the butter and garlic into a small bowl and stir well. Spread the butter evenly onto each slice. Sprinkle with Parmesan if desired. Place on a baking sheet and broil for 3 minutes until butter is bubbly and lightly browned. Garnish with fresh parsley if desired.