Use canned 100% pumpkin puree, not pumpkin pie filling. Pie filling is already sweetened and spiced and turns the dip cloying and loose.
Thaw the whipped topping overnight in the refrigerator, never in the microwave or on the counter. Melted topping will not fold.
Fold, do not whip. Beating collapses the air and leaves you with soup.
Serve with graham crackers, gingersnaps, vanilla wafers, apple slices, or pretzels for a salty contrast.
Keeps 3 days covered in the refrigerator. Never freeze it. The whipped topping breaks on thawing and the dip turns watery.
If the batch is loose, fold in softened cream cheese one tablespoon at a time until it tightens.