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.
