In the Lemon Polenta Cake recipe could I separate the eggs and whisk the egg whites and fold them in to try to make the cake lighter? Thanks.
Nigella's Lemon Polenta Cake (from KITCHEN) is a gluten-free cake made with polenta (or fine cornmeal) and ground almonds (almond meal). Although the cake contains a little baking powder its texture is not as light as a regular sponge cake, but this is offset by the cake's citrussy dampness and tender texture.
It is possible to separate the egg whites out, whisk them and then fold them into the cake batter at the end. But we suspect that it will not alter the finished texture of the cake that much. As the cake contains no gluten, there is nothing to set around the air bubbles in the cake and hold them in place, so the cake sinks back as it cools. With whisked egg whites included in the cake batter, the air in the whites will expand in the heat of the oven and cause the cake to rise quite dramatically, but the cake will sink back even more as it cools. So there is a risk that the cake will end up with a crater in its centre once it has cooled and with just a very slightly lighter texture. On balance it is not something we would particularly recommend.