In a large mixing bowl, whisk together 4 large eggs, 1 cup milk, 1 tablespoon vanilla extract, and 1 teaspoon ground cinnamon until smooth.

Preheat a non-stick skillet or griddle over medium heat for about 2 minutes, then add 1 tablespoon butter and let it melt.

Dip each of the 8 slices of bread into the egg mixture, allowing it to soak for a few seconds to absorb the custard.

Place the soaked bread slices on the hot skillet and cook the first side for about 3 minutes, or until golden brown.

Carefully flip each slice using a spatula and cook the other side for 2 to 3 minutes until golden.

Repeat the process with any remaining slices, adding more butter as needed to prevent sticking.

Serve the French toast hot, topped with syrup, fresh fruit, or whipped cream as desired.