Cream butter and sugar together until light and fluffy.
Add the vanilla and crushed pineapple puree. Bleng well.
Sift together the flour, baking powder and salt and add to the butter mixture. Blend well.
Mix in the the water.
Gently fold in the stiffly beaten egg whites
Bake in a 10-inch tube pan for about 30 minutes or until all test prove the cake to be done. Allow the cake to cool completly before frosting.
To make the frosting, microwave the chocolate and the cream in a medium, microwave-safe bowl on MEDIUM-HIGH power for 1 minute; stir. Microwave at additional 10 to 20-second intervals, stirring until completly melted and smooth.
Transfer the mixture to a large mixer bowl and allow to cool to room temperature.
Beat in butter until creamy then gradually beat in powdered sugar until light and fluffy. Top off your cake with bits of pineapple.