Preheat the grill to hot and grease and base line a 12-hole mini sponge tin

To make the cake batter, whisk the egg whites and salt together until stiff peaks form. Set aside. In a separate bowl, whisk the egg yolks and sugar together until pale and mousse-like. Pour the cooled melted butter into one side of the bowl and whisk in. This will take a good few minutes with an electric whisk, so be patient. Whisk in the lemon zest and vanilla and sift over the flour before folding it in

Fold the beaten egg whites into the mixture until fully incorporated. Be careful not to knock the air out of the batter

Pour a scant spoonful of mixture into each cake hole and evenly spread. Pop the tin in the oven for 2 minutes, or until the mixture is golden. Pour another scant spoonful of mixture over the layer of cake and spread it evenly over the top. Return the cake to grill and cook until golden. Continue for a further six layers, or until you have no room left in your cake tin

Once all the cakes are cooked, leave in the tin on top of a wire rack for a few minutes before taking the cakes out of their tins and leave to cool completely on a wire rack

Melt the apricot jam in a pan before brushing over the cold cakes with a pastry brush. Leave to cool again

In the meantime, make the chocolate glaze. Put all of the ingredients in a heatproof bowl over a pan of barely simmering water and stir until everything has melted and the mixture is smooth and glossy. Leave to cool until the glaze is still just warm

Pour the cooled glaze over the cakes, using a palette knife to nudge the chocolate down the sides of the cakes. Leave to set

To make the vanilla icing, mix together the ingredients until you have a smooth and runny, but not watery, icing. Pop the icing in a piping bag and snip the end off. Drizzle the icing over the top of the chocolate-coated cakes and, again, leave to set