1Preheat oven to moderate, 180 C. Lightly grease and line a 10 x 20 cm loaf pan.
2Sift flour and cinnamon together into a large bowl. Stir in sugar. Make a well in the centre.
3In a bowl, combine banana, butter, eggs, milk and vanilla. Pour into flour mixture. Fold together lightly to combine.
4Pour half mixture into pan. Dollop over half Nutella and use a skewer to swirl through batter. Repeat with remaining mixture and Nutella.
5Bake 55 to 60 mins, covering with foil if over-browning, until cooked when tested with a skewer. Cool in pan 5 mins before turning onto a wire rack to cool completely. Serve sliced, with butter, if liked.
Photo: Bauer/Rob Shaw