Gluten-free Lemon Drizzle Cake (from my sister-in-law - the comments are hers

)
200 gr. butter (room temp.)
200 gr. golden castor sugar
4 eggs
175 gr. ground almonds
OR
175 gr. polenta (I haven't tried it with this)
250 gr. mashed potatoes (absolutely NO lumps! Ricer is good for this)
zest of 3 lemons
2 teasp. gluten-free baking powder
For the drizzle:
4 tblsp. granulated sugar
juice of 1 lemon (one of the above)
Beat sugar and butter together, gradually add the egg.
Fold in the almonds/polenta, potatoes, lemon zest and baking powder.
Pour the mixture into a 20cm. lined cake tin.
Bake for 40 to 45 mins. at 180 degrees.
Leave to cool ever so slightly. Mix together the ingredients for the drizzle and spread over the cake, leave to cool completely in the tin.
My (her!) own observations:
Ground almonds come in bags with 200 gr. so I use the whole bag, and to stop the cake becoming bitter I therefore add another 25 gr. of the castor sugar.
It does make a difference to use golden castor sugar. I tried ordinary castor sugar but it isn't as nice.
The cake rises quite a lot, so I often make two out of the one recipe quantity, which are then flatter which is nice because you don't end up with a huge slice - and you get more of the lemon drizzle per portion! I make a double portion of the drizzle - the recipe calls for the rind of three lemons, so there's plenty to make the juice from. You need to pour the drizzle on while the cake is still very hot so the sugar sort of melts and caramelizes a bit on top.
For us I don't bother with gluten free baking powder because we are not that badly allergic, only some intolerance, so a little is OK. But you can buy gluten free in all supermarkets in the 'Free from' section.