Prep the pan: Line a 9x13-inch baking dish with parchment, leaving overhang on the long sides. Lightly spritz with nonstick spray so layers release cleanly.

Arrange the base layer: Unwrap ice cream sandwiches and place them snugly in a single layer across the bottom. Trim one or two sandwiches if needed to fit the edges tightly.

Soften the ice cream: Let the vanilla ice cream sit at room temperature for 10–15 minutes, until easily spreadable but not melted. A soft, scoopable texture prevents tearing the base layer.

Spread the ice cream: Dollop softened ice cream over the sandwiches and gently spread into an even layer. Work quickly to keep everything cold.

Add sauces: Drizzle chocolate fudge sauce over the ice cream. If using caramel, add a few thin ribbons. Lightly swirl with a knife for a marbled effect.

Sprinkle mix-ins: Add crushed cookies, candy, or mini chips. Aim for even coverage so every slice gets texture.

Whipped layer: Spread half to all of the thawed whipped topping over the mix-ins, depending on how tall you want the middle layer. Smooth the surface with an offset spatula.

Top with more sandwiches: Create a final layer with remaining ice cream sandwiches, lining them up neatly. Press down gently to compact the layers.

Finish and garnish: Spread a thin layer of the remaining whipped topping over the top. Drizzle more fudge and add sprinkles or mini chips. A light pinch of sea salt enhances flavor.

Freeze until firm: Cover tightly with plastic wrap or foil. Freeze for at least 4 hours, preferably overnight, until completely set for clean slices.

Slice and serve: Lift the dessert out using the parchment overhang. Run a sharp knife under hot water, wipe dry, then cut into bars. Serve immediately.