Beat the butter and sugar together until pale and fluffy, then beat in the vanilla extract.
Add the eggs, one at a time beating well after each addition.
Add the banana, flour, cinnamon and golden syrup and fold in until just combined.
Spoon the mixture into 900g loaf tin and bake for 50 minutes–1 hour or until cooked when tested with a skewer, which should come out clean when inserted into the centre of the cake.
Cool in the tin for 20 minutes before transferring to a wire rack to cool completely.