Lightly grease the bottom of a 9×13-inch baking pan with cooking spray and set aside. If using whole graham crackers instead of prepackaged crumbs, place the crackers in a food processor and pulse until fine crumbs form. Transfer the crumbs to a medium mixing bowl. Add the melted butter and salt to the graham cracker crumbs and mix with a rubber spatula until the crumbs are evenly moistened.
Gradually add the powdered sugar and beat until fully incorporated. Fold in 8 ounces of thawed Cool Whip with a rubber spatula. Spread it evenly over the prepared graham cracker crust. Place the sliced bananas evenly over the cream cheese layer. Add the sliced strawberries evenly over the bananas and then add an even layer of the crushed and drained pineapples.
Leftovers of this dessert can be stored in an airtight container in the refrigerator for 2 to 3 days. Any longer, and the crust may start to get soggy.