Recipes are like chemical formulas: change one ingredient or leave out one step, and the result is completely different.
If you are lucky enough to live near a Trader Joe's, pick up a loaf of TJ's pain rustique bread. Amazing. Try not to eat it on the way home. Also, buy TJ's Canadian maple syrup. If no TJ's close by, buy a bakery loaf of French bread, such as a peasant loaf or similar —white, not whole wheat. TJ's pain rustique is full of big air holes, and is chewy, which is important for the outcome of this recipe.
Beat together then pour into a shallow dish:
4 egg whites + 1 egg yolk
3 tablespoon skim milk
1 teaspoon vanilla
3 tablespoons maple syrup
To accelerate the process, I wrap the bread in a wet paper towel and nuke it on high setting in a microwave. The bread then becomes very soft and soaks up the egg mixture much faster.
Take 4 slices of pain rustique and place them in the egg mixture and allow to soak 10 minutes or more to absorb as much of the egg mixture as possible. Lightly coat a warm undamaged non-stick skillet with butter by holding the butter stick in your hand to control the amount, and apply evenly: don't just throw a big pat of butter in the pan.
Get the pan nice and hot, then place each slice of bread —make sure the bread is fully absorbed with the egg mixture— and cook on medium high, standing there to keep an eye on it. After one minute you can turn the heat down to a low setting, and put a lid on it. Experience will tell you how long to cook it, so on your first try, keep vigilant. You want it to cook slowly because only then will the egg mixture set like custard. When it looks firm and feels so by poking it, turn it over and cook the other side. It takes 12-16 minutes or more for me to cook this on a gas stove, but electric is trickier because of slow response to heat adjustment.
The end result should be a crispy outside with buttery taste, and a sweet, tender, firm custard-y interior. If it doesn't cook long enough. the interior will instead be soggy.
Remove the French toast from pan when done and add any remaining egg mixture to the pan to quickly cook that, and add it to the plate. Douse with more maple syrup to taste. Crunchy outside, creamy, firm custard inside: when you get it right, it is out of this world.