Crystallized ginger (also called candied ginger) is fresh ginger that's been boiled in a sugar syrup, then dipped in sugar and dried.
It imparts a fiery sweetness to foods when used as a garnish or when added to baked goods and sauces. For a sweet-hot treat, it can be dipped in melted bittersweet chocolate, allowed to dry, and served as part of a dessert tray. Look for crystallized ginger in the baking aisle or near the herbs and spices in your local supermarket. Don't buy pieces that are hard, stuck together, or missing their sugar coating; these signs indicate the ginger is either old or of poor quality.