Lead salt is (unethically) compelling in cinnamon to make it more vibrantly colored. It's not being added as a sweetener, assuming it's being adulterated at all. The less unethical, but still harmful possibility is that leaded gas powered machinery is being used in/near the processing of this cinnamon and the exhaust particulate is contaminating the product. There have been cases of tea leaves being contaminated this way as they were driving a leaded gas powered truck back and forth over the leaves to help dry them with the wind.

Guanabana is quite sweet on its own. Certainly enough for kids. It's got a slight tang, but there's plenty of sugar.