Line a 9×13-inch baking pan with aluminum foil, leaving a generous overhang on all sides. This overhang is important — it makes lifting the finished bars out of the pan completely effortless. Lightly spray the foil with non-stick cooking spray.
Step 2: Build the First Cracker Layer
Arrange a single, even layer of club crackers across the entire bottom of the prepared pan. Cut crackers as needed to fill any gaps and ensure the entire surface is covered. This cracker layer forms the crunchy foundation of the bars.
Step 3: Make the Caramel Mixture
In a large saucepan, melt the butter over medium heat. Add the graham cracker crumbs, brown sugar, granulated sugar, and milk. Stir everything together and bring the mixture to a full boil. Once boiling, cook for exactly 5 minutes, stirring constantly the entire time — this is critical for the caramel to set properly. Do not stop stirring and do not rush this step.
Step 4: Layer the Caramel and Crackers
Spread half of the hot caramel mixture evenly over the first layer of crackers. Add a second single layer of crackers on top, pressing them down gently. Pour and spread the remaining caramel mixture evenly over this second cracker layer. Finish with a final third layer of crackers placed on top.
Step 5: Make the Chocolate Topping
In a small saucepan over medium-low heat — or in a microwave-safe bowl in 30-second intervals — combine the peanut butter, chocolate chips, and butterscotch chips. Stir continuously until everything is completely melted and the mixture is smooth and glossy. Pour and spread this chocolate topping evenly over the final cracker layer, covering it completely.
