Preheat the oven to 180°C fan / 200°C conventional. Line a 2lb loaf tin with greaseproof paper (see notes on how to do this in the blog postabove).
Mash the bananas together with a fork until smooth and free of lumps.
2 medium Ripe bananas
In a large bowl, beat the butter and sugar together until smooth and pale in colour.
150 grams Unsalted butter or margarine, 120 grams White caster sugar
Crack in the eggs and add half of the flour. Mix until combined.
2 large Eggs, 200 grams self-raising flour
Add the remaining flour and the cinnamon. Fold together until the mixture fully combined.
2 teaspoons ground cinnamon
Fold in the mashed bananas.
Remove the lid and foil from your Nutella jar. Pop in the microwave for 10 seconds to melt it slightly.
100 grams Nutella
Spread half of the banana mixture into the loaf tin.
Spoon 2 tablespoons of melted Nutella down the middle of the cake.
Spoon the remaining banana mixture on top, spreading it out to conceal the Nutella.
Now dot spoonfuls of Nutella on top and use a skewer or knife to swirl everything together.
Bake in the centre of the oven for 40-50 minutes. The banana bread should have risen and browned on top. A toothpick instead in the middle should come out clean of cake mixture, if the toothpick has a little melted Nutella on in that is okay.
Leave to cool in the baking tin for at least 1 hour, before transferring to a wire rack to cool completely.