Preheat the oven to 350°F (175°C). Line your baking dish with parchment paper for easy removal.
Prepare the crust: In a bowl, combine crushed cookies/graham crackers with melted butter. Mix until it resembles wet sand, then press firmly into the bottom of the baking dish to form an even base.
Pour sweetened condensed milk evenly over the crust. Spread gently with a spatula if needed.
Add the toppings: Sprinkle chocolate chips, pour caramel sauce in thin ribbons across the top, then scatter toffee bits and chopped nuts (if using).
Bake for 25–30 minutes, or until the edges are golden and bubbly.
Cool completely before slicing. For cleaner cuts, chill in the fridge for at least 1 hour before serving.