Heat the oven to 190C. Lightly butter a 4-cup capacity oven-proof dish.
Peel, core and slice apples. Place in a saucepan with water and sugar, cover and cook until apples are soft, about 8 minutes. Add blackberries or frozen boysenberries, gently stir through and place in ovenproof dish and keep hot.
Place butter and caster sugar in a bowl and beat until pale and creamy. Add egg and beat well. Sift flour and baking powder together and fold into creamed mixture. Add milk (you should have a mixture with a soft, dropping consistency), using a little more if necessary.
Spoon mixture over hot fruit and bake for 30 minutes or until the sponge is golden and springs back when lightly touched.
Sift over icing sugar and serve hot with vanilla custard (recipe below) or fresh cream.
Vanilla custard
Place the milk and vanilla pod in a heavy-based saucepan and bring up to scalding point. Remove from heat and leave milk to cool and infuse with vanilla.
Place egg yolks and sugar in a bowl and stir well. Pour on milk, mix well then return to rinsed-out saucepan. Place over medium heat and stir continuously until custard begins to thicken slightly. Do not allow to boil or your custard will curdle.
Strain into a jug for serving. Vanilla pod can be rinsed, dried and kept in refrigerator for one more use if wished.
Kathy's tip
This custard is of a pouring consistency. To make custard a little thicker, add 1 tsp of arrowroot to egg yolks and sugar. This will also help stabilise custard, but you still can’t let custard boil or it will curdle. If not serving the custard straight away, sprinkle surface with a little extra caster sugar to prevent a skin from forming.
