Can I substitute polenta with semolina in the Lemon Polenta Cake? I used the instant variety of polenta but it tasted grainy, almost uncooked in the end despite baking for 50 minutes.
Nigella's Lemon Polenta Cake (from KITCHEN) is a gluten-free cake made with polenta and ground almonds (almond meal). Because of the ingredients used the cake will have a different texture to a cake made with flour. It will be crumbly and tender, with a slightly coarse grained texture from the polenta and almonds. Nigella mentions in the recipe introduction "the flavoursome grittiness of the polenta and tender rubble of ground almonds".
We would mention that the recipe specifies fine ground polenta or cornmeal. Some of the "instant" polentas are made with pre-cooked maize and so may not be quite the same. You may be able to use semolina as an alternative for the cake, but as we have not tried this ourselves we are unable to recommend semolina as an alternative to polenta. Also bear in mind that semolina is made with wheat, so the cake will no longer be gluten-free.