The Butterbeer Latte:
To get your hands on a butterbeer latte, you should order a whole milk steamer with two shots of espresso, two shots of caramel syrup, three shots of toffee nut syrup and three shots of cinnamon dolce syrup.
Ask for whipped cream and caramel crumbs on top to complete the beverage. [Source]
And if you want to try the Butterbeer Frappuccino then:
Order a Creme Frappuccino blended with three pumps of caramel syrup and three pumps of toffee nut syrup (if you’ve gone for a grande size).
If you want to make the drink a bit spicier, add a pump of cinnamon dolce syrup and a sprinkle of cinnamon on top.
There's also Harry Potter's Pumpkin Juice: