By the time the whites of these baked eggs were properly cooked, the yolks were rubbery. Build me up, buttercup. Don't break my heart.
Why This Recipe Works
For the sake of convenience, we opted to bake our Breakfast Buttercups in muffin tins instead of individual ramekins. Pretoasting the bread in the oven before adding the egg, cheese, and meat, and switching from large to medium eggs, prevented the eggs from turning the bread cups into soggy mush.
To ensure the whites cooked through without overcooking the yolks, we warmed the eggs in their shells with hot tap water. Just to be safe, we removed the buttercups from the oven a few minutes before they were done and tented them with foil to let the eggs finish cooking by residual heat.