[KyleGoetz]

You should know that どっち is casual, so if you don't mean to sound casual, you should use どちら. どっち comes from どちら.

TO miss X = Xが恋しい

So, depending on your precise intent, something like
イギリスのお菓子の中でどちらが１番恋しいでしょうか 。
This is asking for the #1 sweet missed the most.