Summarize this article in one sentence.
The heat will help solidify the foam. Do not microwave the jar with the lid on, or you may ruin your microwave. Add a sprinkle of some cinnamon or cocoa powder on top of the foam. For something sweeter and fancier, add a drizzle of caramel or chocolate syrup instead.

Summary:
Open the jar, and microwave it for 30 seconds. Add some garnish, if desired, and serve.