Preheat oven to 180 C / Gas 4. Grease and flour a 20x30cm baking tin.
In a large bowl, mix together the flour, sugar, bicarbonate of soda, salt and cinnamon. Make a well in the centre and pour in the chopped pineapple, eggs, oil, bananas and 1 teaspoon vanilla. Stir in the cherries. Mix well and pour into prepared tin.
Bake in the preheated oven for 30 to 35 minutes or until a skewer inserted into the centre of the cake comes out clean. Ice cake while still warm.
To make the icing: Combine melted butter, 1 teaspoon vanilla and icing sugar. Beat in milk, one tablespoon at a time, until desired consistency is achieved.