Place the banana chips in a large bowl with the remaining dry ingredients. Whisk together all the remaining ingredients in a jug.
Pour the wet ingredients into the dry ingredients and stir until barely combined. Divide the mixture between the greased or paper case-lined cups of a 12-cup muffin tin and bake in a preheated oven, 180˚C (350˚F), Gas Mark 4, for 18–22 minutes until risen and firm to the touch. Transfer to wire racks to cool slightly and serve warm.