Making your own chocolate syrup is almost easier than buying chocolate syrup. One thing I have learned, however, is that this is not a recipe that does well when doubled or tripled. I think the sugar doesn't dissolve enough or something because when I attempted to triple the recipe it turned out gritty and not very good. I love this recipe because it is simple. It comes out just like Hershey's syrup so it's great on ice cream but makes great chocolate milk. You end up with about 1 cup of syrup with this recipe and it stores easily in a glass jar in the fridge.
1/4 cup water
1/2 cup sugar
1/4 cup cocoa
Boil water. Add cocoa and sugar. Heat until dissolved, stirring constantly.