Can I Use Hershey's Syrup Instead Of Cocoa Powder?

Depends on what you're doing - for hot cocoa, sure. Works fine. For cookies, maybe and maybe not. Keep in mind that Hershey's Syrup is a mix of cocoa, water, corn syrup, and sugar - cocoa powder is just cocoa powder. It's a dry ingredients not a liquid. So, the liquid and dry proportions of whatever recipe you're using would have to be adjusted. That's usually more work than I want to do. There are, however, some recipes that specifically use Hershey's syrup instead of cocoa for things like brownies - check the Hershey website for tons of stuff using their products.