Preheat the oven to 350°F (175°C). Line a baking dish with parchment paper.
In a mixing bowl, combine melted butter, graham cracker crumbs, brown sugar, granulated sugar, and salt. Press firmly into the bottom of the baking dish.
Bake for 10 minutes, then remove from oven and let cool slightly.
Pour caramel sauce evenly over the crust, then sprinkle with crushed Butterfinger candy.
Drizzle melted chocolate over the top and spread evenly.
Refrigerate for at least 2 hours until set. Cut into bars and serve.