STEP 1 Melt the butter, sugar and vanilla in a medium sized saucepan.
STEP 2 Remove from heat.
STEP 3 Add mashed bananas and stir through until just blended.
STEP 4 Add egg and mix in well. Stir in flour, add milk and mix lightly.
STEP 5 Bake at 170C for approximately 40 minutes.