Line the bottom and sides of an 8-inch square baking dish with parchment paper. Lightly butter the parchment.
In a small saucepan, combine the cream, butter, vanilla extract, vanilla bean seeds, pods, and fleur de sel. Heat over medium-high heat and bring to a boil. Remove from the heat and set aside.
In a medium saucepan, combine the sugar, corn syrup, and water. Heat over medium-high heat, stirring occasionally until the sugar is dissolved. Boil, without stirring but gently swirling the pan occasionally, until the mixture is a light golden caramel color.
Remove the vanilla bean pods from the cream mixture and carefully stir the cream mixture into the caramel – the mixture will bubble up, so pour slowly and stir constantly. Continue simmering the mixture until it registers 248˚ F on a candy thermometer. Immediately remove from the heat and pour into the prepared pan. Let cool for 30 minutes, then sprinkle lightly with additional fleur de sel. Continue to let sit until completely set and cooled. Cut into 1-inch pieces (a buttered pizza cutter works well). Wrap the individual caramels in small pieces of wax paper, about 4-inch squares.