Preheat oven to 180 degrees C. Grease a slice or lamington tin.
In a large bowl, cream together the butter and sugar until smooth. Beat in the eggs, one at a time, then stir in the sour cream and vanilla. Combine the flour, bicarb and salt then stir into the batter. Finally, mix in the mashed banana. Spread evenly into the prepared tin.
Bake for 20 to 25 minutes in the preheated oven, until a skewer inserted into the centre comes out clean. Allow the slice to cool completely before icing with the cream cheese icing.
Cream Cheese Icing: In a medium bowl, cream together the cream cheese and butter until creamy. Mix in the vanilla, then gradually stir in the icing sugar. Store in the fridge after use.
such a good recipie! I doubled it, and 1 1/2'ed the icing ... so yum. Lovely and soft and moist with a great taste. mine came out deeper like a cake rather than a slice, glad i had baking paper to hold it in. everyone wanted more - i had to hide it. will be a popular and regular choice in my kitchen. - 29 Jan 2012