Skin and mash the bananas. Add sugar and water and cook with butter, stirring constantly, until the mixture begins to thicken. Remove the pan from the heat and test by cooling a little of the mixture on a plate. If it can be stretched it is cooked. Mix the cardamoms into the bananas. Spread on a greased, shallow, tin and cool for 15 minutes. Then cut into squares. Decorate with chopped raisins.
Note: Preparation time 10 minutes, Cooking Time 1hour, To Serve 4