In a medium mixing bowl, stir together the graham cracker crumbs, brown sugar, and butter until evenly combined (the mixture will be crumbly).
Spray an 8-inch x 8-inch square pan with non-stick cooking spray. Press 2 cups of the graham cracker mixture into the bottom of the pan to form a crust. Set aside the remaining crumbs. Place the crust into the fridge while you make the filling.
In a large mixing bowl, beat together the cream cheese, butter, and powdered sugar until smooth and creamy. Scrape down the sides of the bowl as needed.
Fold in the crushed pineapple until evenly distributed. Spread the pineapple filling in an even layer over the crust.
Spread 2 cups of Cool Whip over the filling. Cover the dish with plastic wrap and chill in the fridge for at least 4 hours.
Sprinkle the reserved graham cracker crumbs over the top of the dessert. Cut into 9 slices and serve topped with more Cool Whip and a piece of pineapple for garnish, if desired.