Agree… ditch the readymade syrups, or at least switch to a high end brand using REAL ingredients and suger instead of the stupid corn stuff.
By far the best mocha I have ever had, I watched carefully how he made it. They used handmade bean to bar dark chocolate “callets” (flattish round “pucks”, maybe 3/4 inch across and 1/8 or 3/16 inch thick at centre). He COUNTED them out for the proper dose, placing them into the cup, then gently poured in warmed but not steamed/expanded milk, maybe ain inch in the bottom of the cup, and carefully used the heat of the milk to melt the chocolate. THEN he steamed/expanded (properly) a pitcher of whole milk, and when ready carefully poured it into the cup with the melted chocolate and warmed milk. Did not stir, let the pour blend it. Last he added two double shots of their preferred espresso for the mocha… happened to be a washed Pacamara from El Salvador.
One could come quite close by sourcing a quality chocolate callet, I’d get with A. guittard chocolate near San Francisco. DON"T just use Hershey’s… Girardellis would do, as would Callebaut. Make mochas like that and folks would rave to their friends, bring them round to experience it. Its been four years since I had that one, and I STILL remember it.