• ⅔ cup milk
• 2 large eggs
• 1 teaspoon vanilla extract (Optional)
• ¼ teaspoon ground cinnamon (Optional)
• salt to taste
• 6 thick slices bread
• 1 tablespoon unsalted butter, or more as needed

Whisk milk, eggs, vanilla, cinnamon, and salt together in a shallow bowl. Lightly butter a griddle or skillet and heat over medium-high heat. Dunk bread in the egg mixture, soaking both sides. Transfer to the hot skillet and cook until golden, 3 to 4 minutes per side.