In a 12oz. size cup the serving of the syrup is approximately 3 Tbsp. All this beverage is is Starbucks Cinnamon Dolce Syrup topped with steamed apple juice (yes, Tree Top) then whipped cream and caramel drizzle. This is true for all company-owned Starbucks. I'm not sure about those outside of the U.S. or licensed stores.
You can buy cinnamon dolce syrup at your local Starbucks. They do,in fact, sell their syrups if they have enough available (that being said, they do not sell white mocha, mocha, pumpkin spice, etc.).
If you cannot steam your apple juice, simply heat it over the stove. The act of steaming apple juice is simply to make it hot unlike milk which will produce a nice mild flavor and creamy foam. In short, you will get the same results for the most part heating over a stove.
To achieve Starbucks-style whipped cream, all you need to do is head on over to your local cooking store or Williams Sonoma and purchase the canisters we use. They even sell the N20 cartridges that we use. If you don't want to spend 150.00 to make whipped cream, then I'm sure whipped cream out of a can will work fine.
As for caramel drizzle, you can melt your own caramels and drizzle over it or do the easier thing by going to Starbucks and buying their caramel drizzle. They have a retail version for sale in a bottle. They tend to sell out fast though.