Taking a rolling pin, roll each slice of bread out until it’s flat and thin.
Line each loaf pan with 3 slices of bread cutting to fit as needed. You will want the bread to extend just slightly above the rim of the pan.
Place 3 slices of cheddar along the inside of the bread trying to cover up the sides and corners. It may not cover the entire thing; that’s OK.
Place 2 slices of ham on top of the cheese and up the sides of the pan. Essentially you want to line the inside of the pan with layers covering all surfaces. If your ham is smaller, you may need an additional slice per pan. My ham was about 5” round.
Evenly divide the shredded cheese and spinach on top of the ham just covering the bottom.
Carefully place 2 egg yolks in each of the loaf pans.
Pour the egg whites in the well over top of the egg yolks until they are about 1/4” from the top of the pan. You’ll have extra egg whites so save them for another use.
Bake for 25-35 minutes or until the yolks have barely set and the whites are no longer translucent and have very little jiggle left to them. The eggs will firm up completely as they cool.
Remove from the oven and allow to cool completely on a rack before removing from the pan.
Once cooled, remove from the pan with an offset spatula.
Slice and serve. These can be eaten room temperature or warmed.