Heat a large skillet or griddle over medium heat. Slice the French bread into 1/2 inch slices. Set aside.In a large bowl or dish, combine egg yolks, milk, vanilla and cinnamon with a whisk. Dip each slice of French bread into the mixture, coating both sides. Remove from dish and repeat with all bread slices.

Swipe butter all over the hot griddle and then add coated bread slices. Cook French toast on each side for 2-3 minutes, or until golden-brown. Watch closely so they don't burn!

Serve French toast immediately with butter, warm syrup and powdered sugar. Enjoy!