Preheat oven to 350 °F. Use a rolling pin to crush crackers in a sealed plastic bag. Separate 4 eggs and place whites into large mixing bowl (discard yolks). Add pinch of salt to egg whites and beat until stiff. Continue beating and gradually add sugar, baking powder and vanilla extract until mixture stands in peaks. Fold in crushed crackers, coconut flakes and chopped macadamia nuts. Spray muffin tin with non-stick spray. Spoon mixture into muffin tin cups and make a small 'bowl' in the center of each with a spoon. Place in oven to bake for 18-20 minutes until light golden brown. Remove from oven and allow to cool before serving Meanwhile, remove mango flesh in small (1/4 inch) cubes. When ready to serve---top each puff with a dollop of whipped cream and a heaping spoonful of cubed mango. Enjoy!