Preheat the oven to 180C, 350F, gas mark 4.
Whisk the egg whites until stiff. Add the yolks and whisk in. Add the caster sugar and whisk until all the suger has dissolved.
Sift the self raising flour with the cocoa powder. Using a figure of eight action, fold half the flour into the egg & sugar mixture. When the flour is almost folded in, add the remaining flour in the same way until the mixture is smooth. Place to one side
Spoon the pie filling onto the base of a lightly greased casserole dish. Spoon the sponge mixture over the top. Bake in the oven for approx 40 minutes or until golden brown.
When cooked, leave to cool for a few minutes then loosen the pudding with a palette knife and turn out onto a flat dish.
Serve with low fat fromage frais or ice cream