Preheat the oven to 180 C / Gas 4. Grease a 23cm cake tin.
Cut apricots in half and stone them.
Sprinkle one-fifth of the sugar over the bottom of the cake tin.
Arrange the halved apricots on top of the sugar with their cut side up so that the base is covered.
For the cake mixture, cream margarine and sugar together. Beat both eggs and add to mixture, then add sifted flour. If the mixture is too stiff, fold in milk. Add it to the top of the apricots and level off the top.
Bake until the cake is golden and the apricots are cooked through, 45 to 60 minutes.
Remove from oven and allow to cool. If you remove the cake from the tin before it is cold the cake will likely collapse.
To unmould it, loosen the sides of the tin then put a plate on top and turn the cake upside down.
Slice and eat on its own or with vanilla ice cream.