01 - Preheat oven to 375°F (190°C) and lightly grease a 6-cup muffin tin.
02 - Combine softened butter, minced garlic, and chopped parsley in a small bowl.
03 - Flatten each bread slice with a rolling pin and trim crusts if needed to fit into muffin cups.
04 - Spread garlic butter over one side of each bread slice, then gently press butter-side up into the prepared muffin cups to form a nest.
05 - Sprinkle a portion of grated Parmesan into the base of each bread cup.
06 - Crack one egg into each bread cup, season with salt and black pepper, and sprinkle with shredded cheese if desired.
07 - Bake for 16 to 18 minutes, until egg whites are set and yolks reach preferred doneness.
08 - Let egg cups cool for 2 minutes, then gently lift each from the tin using a small spatula.
09 - Serve warm, garnished with extra fresh parsley as desired.