Prep the pan: Use a 9x13-inch baking dish. For easier slicing, lightly spray with nonstick spray or line with parchment, leaving overhang.

Make the filling: In a large bowl, whisk together the instant vanilla pudding and cold milk for 2 minutes until slightly thickened. Fold in the whipped topping until smooth and fluffy.

First cracker layer: Arrange a single layer of graham crackers on the bottom of the dish. Break pieces as needed to fully cover the surface.

First filling layer: Spread half of the pudding mixture over the crackers. Smooth with an offset spatula or spoon.

Second cracker layer: Add another full layer of graham crackers on top of the filling.

Second filling layer: Spread the remaining pudding mixture evenly over the crackers.

Final cracker layer: Top with a final layer of graham crackers. Press lightly to settle.

Make the chocolate glaze: In a microwave-safe bowl, combine chocolate chips, butter, and corn syrup. Microwave in 20–30 second bursts, stirring in between, until smooth. Stir in milk or cream, vanilla, and a pinch of salt until glossy and pourable.

Glaze the cake: Pour the chocolate glaze over the top cracker layer. Tilt the pan gently to cover the surface, or spread with a spatula for an even finish.

Chill: Cover the dish and refrigerate for at least 6 hours, ideally overnight. This softens the crackers and sets the layers.

Serve: Slice with a sharp knife. Wipe the blade between cuts for clean squares. Enjoy cold.