Plums have an affinity for honey, and vice versa, meaning this smoothie is naturally delicious in more ways than one. It's also made with plain (unsweetened) yogurt, which adds creamy texture and tangy taste, and ice cubes for the ultimate in slushy refreshment. Serve with an additional ice cube (or two) if desired, and a drizzle of honey. Other stone fruit, such as apricots, peaches, or nectarines, would also work here, so use what's freshest and ripest.