Place all ingredients in a large mixing bowl, beat a high speed for about 15 - 20 minutes, or until very stiff. Lightly oil a flat oven-proof dish or tray (I usually use a large shallow pyrex quiche dish about 27cm diameter) and spread mixture in a circle (it will spread a little in cooking so keep mixture in from the edge of the dish a little), making a slight well in the centre. Bake at 300° to 320° for 30 minutes, then reduce the temperature to 220° and bake for another 30 minutes (make sure it does not brown). Turn the oven off, open the door slightly and allow to cool in the oven. Store in an airtight container until ready to use.
Fill with whipped cream and fresh fruit (strawberries, raspberries, kiwi fruit, mangoes, peaches, passionfruit etc.) just before serving.