1. Beat eggs, milk, and cinnamon together. If using, add orange zest and/or Triple Sec. Whisk until well blended. Pour into a shallow bowl.
2. Dip each slice of bread into the egg mixture, allowing bread to soak up some of the mixture. Melt some butter (or use vegetable oil) over a large skillet on medium high heat. Add as many slices of bread onto the skillet as will fit at a time. Fry until brown on both sides, flipping the bread when necessary.