In a sauce pan, combine the sugar, corn syrup, cream, butter and pecans together. Stir over high heat until the sugar dissolves. Stir in the chocolate and boil the ingredients slowly to the firm ball stage, 248 degrees F. Stir in the vanilla. Using a wooden spoon, drop about a tablespoon for each candy onto a parchment-lined baking sheet. Let the caramels cool and set, about 5 minutes. Using a candy dipping fork, dip each caramel into the tempered chocolate. Place the chocolates back on the parchment on allow to set, about 5 minutes.