Preheat the oven to 325 degrees F (165 degrees C). Butter a 9x13 inch baking pan.

In a large glass or metal bowl, whip egg whites with cream of tartar and vanilla until soft peaks form. Gradually add sugar while continuing to whip to stiff peaks. Fold in cracker crumbs and pecans until evenly blended. Spread evenly in the prepared pan.

Bake for 30 minutes in the preheated oven, until the cake springs back when pressed in the center. Cool completely before frosting.

To make frosting: Mix together the crushed pineapple and whipped topping. Spread over cooled cake, and refrigerate until serving.