I have attempted twice to make the Butterscotch Layer Cake, from How To Be A Domestic Goddess, and both times I have found the sponge to be very dense. I use the food processor version. I even sift the self raising flour before adding it to the processor and still no luck. I use good quality flour. I wonder if maybe I need to add a teaspoon of baking powder (as in Nigella's Victoria Sponge recipe). Your help would be greatly appreciated. Michael.
Nigella's Butterscotch Layer Cake (from Domestic Goddess) has cakes layers which are very similar to a Victoria Sponge, but using light muscovado sugar (light brown sugar) as part of the sugar content. It also uses the food processor method for making the cake. A food processor can make a sponge cake a little more heavy, though certainly not inedible unless the batter is processed excessively which causes the glutens in the flour to develop too much and will lead to a tough cake.
The brown sugar may also not be quite fully dissolved which could also affect the texture of the cake. We would suggest processing the muscovado and caster sugar with the butter for a minute or so first, until you can see that the sugars have dissolved, then add the eggs and flour and pulse until just combined. You can also add some extra baking powder if you like, but we would suggest only 1/2 to 3/4 of a teaspoon, as Nigella's Victoria Sponge recipe contains a mixture of self-raising flour (with raising agents) and cornflour (cornstarch) which does not contain any raising agents whereas this recipe uses all self-raising flour.