Combine graham cracker crumbs, margarine, and sugar in a 9x13-inch baking dish. Press cracker mixture into the baking dish with the back of a spoon to form a crust.
Stir pineapple, cherry pie filling, bananas, sweetened condensed milk, coconut, and vanilla extract in a large bowl until evenly mixed. Fold whipped topping into pineapple mixture and spread over cracker crush. Sprinkle with pecans and drizzle with ice cream topping. Refrigerate until chilled, about 30 minutes.