Toasting the oats will improve the flavor of the granola bars, but more importantly it will kill any bacteria that may be present on the raw oats. There has been an increase of infections from raw oats in the last few years, and toasting them is the best way to ensure they’re safe to eat. That being said, it is ultimately up to you if you decide to toast your oats or not. This recipe will work with both toasted and untoasted oats.