Line a 12-section bun tray with paper or foil cake cases, or stand 12 silicone cases on a baking sheet. Put all the cake ingredients in a bowl and beat with a hand-held electric whisk for 1–2 minutes until light and creamy. Divide the cake mixture between the paper, foil or silicone cases.
Bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 20 minutes or until risen and just firm to the touch. Transfer to a wire rack to cool.