Preheat the oven to 160C Fan/180C/Gas 4. Grease and line the base of a 20cm round cake tin.

Combine the ground almonds, potato flour, zest of the a lemon and the baking powder.

Beat the butter and sugar in a free standing mixer until really light and fluffy. Add the egg yolks one at a time, beating in-between.

Tip the almond mixture into the butter and gently mix and fold in.

Whisk the egg whites in a clean bowl until very stiff. Now stir one tablespoon of the egg whites into the batter to loosen it. Fold in the remaining and pour into the prepared tin. Sprinkle the flaked almonds on top. Bake for 40-45 minutes or until a skewer inserted into the cake comes out clean.

Remove from the tin and sprinkle with icing sugar. Serve with Tims Dairy rhubarb and rose yogurt.