01 - Preheat oven to 375°F (190°C). Lightly grease a 6-cup muffin tin.
02 - In a small bowl, mix softened butter, minced garlic, and chopped parsley until evenly combined.
03 - Flatten each slice of bread using a rolling pin. Trim crusts if necessary to fit the muffin cups. Spread a thin layer of the garlic butter on one side of each slice.
04 - Press each bread slice, butter side up, into the muffin wells to shape into cups.
05 - Evenly distribute grated Parmesan cheese into the base of each bread cup.
06 - Crack one egg into each bread cup. Season with salt and black pepper. Sprinkle shredded cheese on top if desired.
07 - Transfer the tin to the oven and bake for 16 to 18 minutes, or until egg whites are set and yolks reach preferred doneness.
08 - Allow to cool for 2 minutes, then use a small spatula to gently release each egg cup from the tin.
09 - Serve warm, garnishing with additional chopped parsley if desired.