Preheat your oven to 350°F (175°C).
Grease a baking dish with butter.
Cut the loaf of bread into thick slices.
In a large bowl, whisk together the eggs, milk, sugar, vanilla, cinnamon, and salt.
Arrange the bread slices in the baking dish, overlapping them slightly.
Pour the egg mixture evenly over the bread, ensuring each slice is soaked.
Let it sit for about 15 minutes to absorb the mixture.
Bake in the preheated oven for 35-40 minutes until golden brown.
Remove from the oven and let cool for a few minutes.
Serve warm with your choice of toppings.