01 - Preheat oven to 375°F. Lightly grease a standard 6-cup muffin tin.
02 - In a small bowl, mix the softened butter with minced garlic and chopped parsley until evenly combined.
03 - Flatten each bread slice with a rolling pin. Trim crusts if necessary to ensure the bread lines the muffin cup without overhang.
04 - Spread a thin layer of garlic butter on one side of each bread slice. Press the bread, butter-side up, into each prepared muffin cup to form a nest.
05 - Sprinkle a portion of grated Parmesan cheese into the bottom of each bread-lined cup.
06 - Crack one large egg into each bread cup. Season with salt and black pepper. Add shredded cheese on top, if desired.
07 - Place muffin tin in oven and bake for 16–18 minutes, or until egg whites are set and yolks reach preferred doneness.
08 - Let cups cool for 2 minutes. Use a small spatula to gently lift each bread egg cup from the tin and transfer to a platter. Garnish with additional fresh parsley if desired.