Use the noun deserts to describe what happens when someone receives what's coming to him — good or bad, he gets his "just deserts."
When you're using deserts to mean "what is deserved," it's pronounced like the banana split kind of desserts. This is because its root is the word deserve. Deserts most often follows the word just, to mean that someone gets the reward or punishment he or she really deserves to get. The bully who is expelled from school gets her just deserts, for example, and so does the brilliant scientist who wins the Nobel Prize.