In a mixing bowl, crack open 5 eggs and add 1 1/2 cups of eggnog. Mix in 1 teaspoon of vanilla extract, 2 teaspoons of cinnamon, and 1/4 teaspoon of nutmeg. Stir everything together until well blended.
Arrange half of the bread slices in a shallow baking dish or a large bowl. Pour half of the egg mixture over the bread, turning each slice until fully coated.
Heat a skillet or griddle on medium-low. Add 1 tablespoon of butter or ghee and let it melt completely. Place as many bread slices as will fit in the pan and toast until golden brown. Flip and repeat on the other side.
Once both sides are toasted, remove the bread and set aside. Melt another tablespoon of butter and repeat with the remaining bread. Continue this process of soaking and frying until all the bread is toasted.
Serve the Eggnog French Toast with warm maple syrup and a sprinkle of nutmeg, preferably freshly grated.