In a mixing bowl, crack the eggs and whisk them until fully combined.
Add the milk, vanilla extract, and ground cinnamon to the eggs, and whisk until smooth.
Pour the egg mixture into a shallow dish or plate that is large enough to fit the bread slices.
Heat a frying pan or skillet over medium heat and add 1 tablespoon of butter.
Once the butter is melted and bubbling, dip each slice of bread into the egg mixture, making sure both sides are well-coated but not soaked.
Place the coated bread slices into the hot skillet in a single layer. Cook for 2-3 minutes on each side, or until golden brown.
Once cooked, remove the French toast from the skillet and keep warm while you cook the remaining slices, adding more butter as needed.
Serve the French toast warm, drizzled with maple syrup and optionally dusted with powdered sugar.