Prep the bread. If your bread is fresh, let slices sit out for 30–60 minutes to dry slightly, or lightly toast them. Slightly stale bread drinks in custard without falling apart. Good absorption = great texture.
Make the custard. In a shallow dish, whisk eggs, milk, cream, sugar, vanilla, cinnamon, and salt until smooth. No streaks, no egg gloops. This is your flavor engine.
Mix the topping. Stir together the cinnamon sugar in a small bowl and set aside. You’ll use it twice: once mid-cook for the caramelized edge, and once at the end for sparkle.
Heat the pan. Preheat a large nonstick or seasoned cast-iron skillet over medium heat. Add 1 tablespoon of butter and a splash of oil. The oil raises the burn point, so the butter doesn’t go diva on you.
Soak the slices. Dip each slice into the custard for 15–25 seconds per side, depending on thickness. Flip gently. You want it saturated but not collapsing like a wet sponge.
Cook the first side. Lay slices in the pan. Don’t overcrowd. Cook 2–3 minutes until the undersides are deep golden-brown. If it smells like toast, good. If it smells like smoke, turn down the heat.
Cinnamon-sugar kiss. Right before flipping, sprinkle a light veil of cinnamon sugar on the top side. Then flip and cook 2–3 minutes more. The sugar will melt and caramelize, creating that coveted crust.
Finish and hold. Transfer cooked slices to a wire rack set over a sheet pan. Keep warm in a 250°F (120°C) oven. This keeps the edges crisp while you cook the rest. Repeat with remaining slices, adding more butter/oil as needed.
Serve like you mean it. Plate with a final dusting of cinnamon sugar, a pat of butter, and warm maple syrup. Add berries or a dollop of whipped cream if you’re feeling extra.