Preheat the oven to 170°C/325°F/Gas Mark 3. Grease a 21 x 11 cm (81⁄4 x 41⁄4 in) loaf tin. Line the base of the tin with baking paper.

Sift the flour, baking powder, sugar and cinnamon into a large bowl. In a separate bowl, whisk the butter, milk and egg together. Add the milk mixture to the dry ingredients with the mashed bananas. Use a wooden spoon to mix until well combined.

Pour the mixture into the prepared tin and smooth the surface with a spoon. Bake for 40 minutes, or until a skewer inserted into the centre comes out clean. Set aside in the tin for 5 minutes before turning out onto a wire rack to cool. Serve warm or at room temperature. Cut into slices, spread with butter and drizzle with a little maple syrup.