If you ever get asked to make a gluten free cake, which is increasingly the case at this end anyway, you might be mistaken in thinking that simply subbing out the flour for a GF variety would do the trick. Technically yes, it will work, but more than likely you will find yourself with a rather dry and crumbly cake, often with a rather starchy aftertaste.
Firstly- best brands I recommend are Shipton Mill and Dove's Farm, both of which you can order online or from some supermarkets. I have tried most of the supermarket own brand versions too, and find them less successful on the whole.
If converting a recipe from wheat based to GF, then as a general rule I would create a ratio of dry goods to include ground almonds along with the flour. Obviously check that nuts are ok to use first! For example- 180g wheat flour is subbed for 110g GF flour and 70g almonds with a tsp of baking powder.
I tend to also add an extra egg to counteract the more absorbent nature of the flour too, that with a splash of milk usually does the trick! The aim for me is to always avoid a dry texture, but also the starchy flavour, and I find the nuts help especially with that. Any recipe with extra flavours in always help too... carrot cake, banana cake, lemon, chocolate... you get the picture! Here is a recipe to get you started!
GF Lemon almond sponge cake
180g unsalted butter
180g caster sugar plus 40g for syrup
4 large eggs
zest and juice of 1 lemon
110g GF self raising flour
70g ground almonds
1tsp GF baking powder
2 tbsp whole milk
1 tsp lemon extract (optional)
Cream together butter, sugar and lemon zest until white and very fluffy. Weigh out the dry ingredients and set to one side.
Add the eggs gradually, if they start to curdle, then add a spoon of flour mix to counteract this. Once all the eggs are added, fold in the rest of the flour mix and milk with lemon extract if using.
Grease and line an 8" deep cake tin, and spoon batter in before smoothing out and creating a slight dip in the centre. Bake at 180C in a convection oven for 25-35 minutes. Take care to keep an eye on GF cakes as they will become very dry if slightly overbaked.
Meanwhile, make syrup by simmering together 40g caster sugar and the juice of your lemon with a splash of water on the hob, until all sugar crystals are dissolved. Set aside to wait for your cake.
Once out the oven, skewer all over to the bottom of the tin and then drizzle your prepared sugar syrup all over the surface of the cake before leaving to cool.