Step 1
Mix the ground almonds and sugars together thoroughly, then gradually add the beaten egg and lemon juice and mix to a stiff paste. Knead until smooth, then roll out on a work surface dusted with a little icing sugar to a diameter just slightly larger than 20cm (8in).

Step 2
Brush the top of the cake with the warm, sieved apricot jam. Lay the circle of almond paste on top, press into place and trim it to fit. Leave for 24 hours before icing the cake.