Crack the eggs into a medium bowl. Whisk the eggs until smooth. Add the milk, cinnamon, vanilla, and salt. Whisk everything together to form a creamy custard mixture.

Dip each slice of sourdough bread into the custard mixture. Let each side soak for around 20-30 seconds, ensuring it absorbs enough custard without becoming too soggy.

Place a large skillet or griddle over medium heat. Add 1 tablespoon of butter and let it melt until it starts to sizzle.

Carefully place the soaked bread slices onto the hot skillet. Cook for about 3-4 minutes on each side, or until golden brown and crispy. Flip only once to achieve the perfect texture. Continue with the remaining slices, adding butter if necessary.

Once all the slices are cooked, plate them and add your favorite toppings such as maple syrup, powdered sugar, fresh fruit, or nuts.