Luscious lemon & raspberry sandwich

Heat oven to 180C/160C fan/gas 4. Grease and line the base of 2 x 20cm non-stick round sandwich tins with baking parchment. Beat 250ml of the yogurt with the oil and eggs. In a large bowl, mix the sugar, flour, polenta, xanthan gum and baking powder until well blended. Pour the yogurt into the flour mixture and stir well. Fold in half the raspberries, then divide the mixture equally between the tins. Level and bake for 25-30 mins until firm and cooked all the way through when an inserted skewer comes out clean. Cover with foil after 20 mins if the top is getting too brown. Cool in the tins.

Whip the cream until just holding its shape, then stir in the remaining lemon yogurt, trying not to knock out any air. Use to sandwich cakes together, with the remaining raspberries scattered inside.

Stir the icing sugar, lemon zest and juice together to make a runny icing. Drizzle over the cake and leave in a cool place to set before serving. Will keep in the fridge for 2 days, return to room temperature before serving.