Heat the oven to 180C/160 fan/gas 4. Put the whole bananas in a food processor and blitz until most of the peel is finely chopped. Add the sugar and blitz again to combine (the abrasive sugar will help chop the peel further before it melts in). Add the oil and eggs, blitz again briefly, then pulse in the flour, ginger and baking powder until everything is well-combined.

Oil a baking tin (we used a round bundt tin, but a loaf tin will also work; you'll need a tin that has a 1.5-litre volume) and pour in the batter. Bake for 40-50 mins (if using a bundt tin; a loaf tin will take about 1 hr) until a skewer inserted into the middle comes out clean. The cake will puff up above the tin but sink back down as it cools, so don't be alarmed.

Leave to cool in the tin on a wire rack for about 30 mins. Remove from the tin while still warm. If you've used a bundt tin, you may need to ease the cake away from the side of the tin and firmly shake it to remove the tin. If you like, drizzle over some melted chocolate. Serve warm or leave to cool completely. Will keep in an airtight container for up to four days.