Glass pans typically do not cook as quickly as their metal counterparts because metal is a conductor of heat, while glass is an insulator. Translation: glass will be slower to heat but once hot does a better job of retaining the heat. While this can result is a more even baking, it can also result in the bottom and edges of especially sugary loaves caramelizing too quickly and burning before the inside is cooked through. The upside of glass is that the transparent walls mean you can visually see how your loaf is browning without removing it from the pan. They are a go-to for classics like banana bread, zucchini bread, and babka.