If you have a light instant coffee or espresso it'll taste more similar to the original, but most instant coffee is dark so it is more similar to traditional espresso drinks.You can skip the syrup and try to dissolve the sugar directly into the coffee and water, but keep in mind it takes quite some time to dissolve, and it may not fully unless you add it to warm water and then cool it with ice. You can use as little or as much brown sugar syrup and oatmilk as you'd like. If you have an espresso maker or a way to make espresso at home, you can substitute in 2-3 shots of espresso for the instant coffee. I don't drink enough drinks with espresso so we haven't made the investment.