Whisk the eggs, milk, orange juice, sugar, orange zest, vanilla, and salt in a shallow dish until fully combined and smooth.
Heat a large skillet or griddle over medium heat. Add a knob of butter and let it melt and bubble slightly.
Dip each slice of bread into the custard mixture. Let it soak for 10-15 seconds per side, ensuring it absorbs the liquid but doesn't fall apart.
Place the soaked slices onto the hot skillet. Do not crowd the pan; cook in batches if necessary.
Cook for 3 to 4 minutes per side until deep golden brown and crispy on the edges.
Serve immediately, dusted with powdered sugar and drizzled with warm maple syrup.
