Whisk the eggs, milk, orange juice, orange zest, sugar, vanilla, and cinnamon in a large shallow bowl until smooth.
Heat a large skillet or griddle over medium heat and melt 1 tablespoon of butter.
Dip each slice of bread into the egg mixture. Soak for 10-15 seconds per side, allowing excess to drip off.
Place the bread onto the hot skillet. Cook for 3-4 minutes until golden brown and crispy.
Flip and cook the other side for another 2-3 minutes.
Serve immediately topped with fresh orange slices, powdered sugar, and syrup.