Preheat the oven to 160C (fan). In a large bowl, add 3 ripe bananas, mashed, 75 grams salted butter, melted, 125 grams soft light brown sugar, 1 egg, whisked briefly, 1 teaspoon vanilla extract, 175 grams very strong bread flour, 1 teaspoon baking powder, 1/4 teaspoon bicarbonate of soda, 1/4 teaspoon sea salt, 1 teaspoon cinnamon, and 3 tablespoons milk. Whisk until the mix just comes together and pour into a lined loaf tin or baking tin.