Crack eggs into a large, flat bowl. Add juice and cinnamon; blend well.
Working quickly, dip each bread slice into egg/juice mixture, turning it to coat both sides.
Transfer coated bread to a plate and dip remaining slices.
Spray large skillet with nonstick spray and heat over medium heat until hot, about 3 minutes.
Add slices of coated bread to hot skillet in a single layer and cook until bread is golden brown and crusted on the bottom, about 2 to 3 minutes.
Flip over and cook until other side is golden, about 2 minutes more. Repeat with remaining slices.
Serve french toast with maple syrup, if desired.
