Step 1: Line a 9x13 inch baking pan with parchment paper, leaving an overhang on the sides for easy lifting. Set aside.
Step 2: In a medium bowl, combine the graham cracker crumbs and melted unsalted butter. Mix until well combined and the crumbs are moistened.
Step 3: Press the graham cracker mixture evenly into the bottom of the prepared baking pan. Use the back of a spoon or your fingers to create a firm, compact crust.
Step 4: In a large microwave-safe bowl or a saucepan over low heat, combine the unwrapped soft caramels and heavy cream. Heat, stirring frequently, until the caramels are completely melted and smooth. Remove from heat and stir in the vanilla extract.
Step 5: Pour the warm caramel mixture evenly over the graham cracker crust in the pan. Spread it gently with a spatula if needed.
Step 6: Generously sprinkle the crushed Butterfinger candy bars over the warm caramel layer, pressing them down lightly so they adhere.
Step 7: Refrigerate the bars for at least 2 hours, or until the caramel is completely set and firm. This is crucial for clean slicing.
Step 8: Once chilled, use the parchment paper overhang to lift the entire slab of bars from the pan. Place on a cutting board and use a sharp knife (warmed and wiped clean between cuts) to slice into squares or rectangles. Serve and enjoy!