TIM'S LEMON TRICKLE MASH CAKE

Steps:

• Preheat the oven to 180°C/gas 4. Butter and line a 23cm diameter springform cake tin. Beat the butter and sugar together until light, pale and fluffy (about 5 minutes in a mixer). Beat in the eggs, one at a time, adding a spoonful of ground almonds with each addition to stop the mixture curdling. Stir the baking powder into the remaining almonds, then fold them into the mixture, followed by the mashed potato and the lemon zest. Spoon the mixture into the cake tin and bake for 30-40 minutes, or until a skewer inserted into the centre comes out with just a few moist crumbs clinging to it. Check it after 25 minutes to make sure it is not colouring too much, and cover with a sheet of foil if it is. Leaving the hot cake in its tin, pierce it all over with a skewer, going quite deep, but not right through to the base. Combine the lemon juice and caster sugar for the topping and, before the sugar has had a chance to dissolve, pour the mixture slowly and carefully all over the cake. Leave to cool completely before serving.