Historically called Saigon cinnamon, Royal Cinnamon is the species Cinnamomum loureiroi, and it has the intense sweetness and spiciness that Vietnamese cinnamon is prized for. Most of what's exported as Saigon cinnamon these days is Cinnamomum cassia, a different species (curiously neither cinnamon grows anywhere near Saigon). Use cinnamon in pastries, hot cereal, buttered toast, and baked goods, or sprinkle into rich, savory meat or tomato-based dishes.