Lightly grease a 9-inch square pan with butter, being sure to get all sides and bottom
In 1-quart saucepan, heat butter, heavy whipping cream, whiskey, vanilla, maple flavoring, and 1/4 teaspoon salt to boiling, stirring frequently. Remove from heat; set aside.
In 3-quart saucepan, mix sugar, corn syrup, and water. Heat to boiling over medium-high heat. DO NOT STIR. Boil until sugar turns a warm golden brown.
When the sugar mixture is done, turn off the heat and slowly add the cream mixture to the sugar mixture. Be careful -- it will bubble up violently. Cook over medium-low heat for about 10 minutes, until the mixture reaches 248 degrees F (firm ball) on a candy thermometer. Pour caramel into pan; cool 10 minutes. Sprinkle with up to 1 tablespoon salt; cool completely.
Rub butter on a pair of kitchen scissors or knife then cut caramels into squares; wrap individually in parchment or wax paper.