In a flat-bottomed pie plate or baking dish, whisk together eggs, milk, vanilla, cinnamon, sugar, and salt. Set aside
Melt 1 tablespoon butter in a large skillet or on a griddle over medium heat.
Place bread slices, one or two at a time, into the egg mixture and flip to make sure both sides of bread are well-coated.
Place coated bread slices in skillet or on griddle and cook on medium heat until golden brown on each side, about 3-4 minutes. Repeat for remaining bread, adding more butter as necessary.
Serve immediately or keep warm in 200°F oven until ready to serve, but no longer than about 30 minutes.
