Cut 7 x 1"/2.5cm slices from the loaf. You really need an uncut loaf for this. Even thick cut bread is not thick enough.
Grate the Cheddar
Put the Cheddar, cream cheese and butter in a saucepan and gently melt. It will curdle, but that doesn't matter
Beat the eggs to a froth
Add the eggs to the cheese saucepan
Dip each slice of bread into the cheesy mixture, making sure every surface is coated.
Place as many slices as you need now on a baking sheet.
Bake in a hot oven for about 25 minutes, turning over half way through. Gas Mark 7 / 425F / 220C / 200C Fan. Or use an air fryer, in a single layer, for about 10 minutes.
Serve immediately
Remaining slices
Open freeze the remaining slices, before wrapping and bagging
You may like to have some snacky cubes. If so, cut as many slices as you want into 1"/2.5cm cubes before dipping and freezing
Cubes will take about 10 minutes in the oven, don't forget to turn over half way through
Any frozen slices or cubes can be baked from frozen, when you will need to add about 5 minutes extra to the cooking time.
Notes
you can substitute a strong and mature cheddar for the parmesan