Sugar is combustable! And candy has a lot of sugar.
Molten Potassium Chlorate + sugar (gummi bear) -> a lot of energy and light. KClO3 is a powerful oxidizer, although this reaction can occur with other weaker oxidizing agents.
6KClO3 (l) + C12H22O11 (s) -> 12CO2 (g) + 11H2O (g) + 6KCl (s)
Molten KClO3 can cause very severe burns. The test tube also often shatters.