Homemade Chocolate Syrup

I was in search of a chocolate milk mix or syrup after Hershey discontinued their chocolate milk mix. (I still miss having that sugary chocolate sludge at the bottom of my cup.) Until recently, my usual supermarket stocked only chocolate syrups made with high fructose corn syrup. I experimented with recipes for hot cocoa mix but they didn't dissolve in cold milk. This recipe checked all my boxes; it's made out of kitchen staples, and because it starts with a simple sugar syrup, it dissolves well in hot or cold milk, and of course it's good on ice cream too (but not as decadent as hot fudge).