I love the cocoa and cinnamon in this recipe... It's so unique and gives the chili such depth of flavor. (epicurious.com)
You won't regret the few extra minutes it takes to brown your butter in return for such a depth of flavor. (fivehearthome.com)
These are used more sparingly in recipes, but add such a depth of flavor when called for — as does Mirin, which doesn't belong under vinegars but is worth a mention. (faring-well.com)