Yogurt Pot Cake Leavening

Our answer

Nigella's Yogurt Pot Cake (from NIGELLISSIMA uses a combination of plain flour and cornflour (cornstarch) and does not use any chemical leavening, such as baking powder or bicarbonate of soda (baking soda). However the cake is not too dense or heavy as the leavening comes from the whisked egg whites. The air trapped in the whisked egg whites will expand as the cake bakes, helping the cake to rise.

It does mean, however, that the egg whites should be folded in gently, to preserve as much of the air as possible. You may find it easier to mix in one quarter of the whisked egg whites first to "lighten" the batter and make it easier then to fold in the remaining egg whites. Then gently pour the batter into the prepared ring mould and bake straight away.