Preheat oven to 170°C. Line a 23cm round cake tin with baking paper or prepare 4 x 10cm tins (recycled large 425g tuna cans are perfect) or 12 muffin tins.
Beat butter and sugar until creamy. Beat in eggs and vanilla then bananas.
Dissolve baking soda in hot milk and add to mixture. Sift over flour and baking powder and fold in.
Spoon mixture into prepared tin(s) and smooth top. Bake until a skewer inserted in the centre comes out clean and the top is springy to the touch.
One large cake will take 50-60 minutes, allow 45-55 minutes for 4 medium cakes and about 20 minutes for muffin-sized cakes.
Cool in tin and ice when cool.
Store in a sealed container in a cool place for 2-3 days or wrap un-iced cake and freeze.
