Cooking oil spray, for greasing
3 Granny Smith apples, peeled, cored, sliced
5 stalks rhubarb, trimmed, sliced on the angle
120g brown sugar
Finely grated zest and juice of ó lemon
1 tsp ground cinnamon
225g plain flour
1½ tsp baking powder
125g caster sugar
140g butter, softened
Extra 2 Tbsp brown sugar
Icing sugar, to dust (optional)
Cream or ice-cream, to serve
Preheat oven to 170 C. Line base of a 22cm round springform cake tin with baking paper, then lightly grease base and side with oil.
Put apple, rhubarb, brown sugar, lemon zest and juice and 1/2 tsp of the cinnamon in a large frying pan over a medium heat. Cook for 5-10 minutes or until fruit is tender and juices have evaporated. Set aside to cool slightly.
Meanwhile, to make pastry, sift flour, cornflour, baking powder and remaining cinnamon into a large bowl. Add caster sugar and butter and mix by hand until combined. Beat in egg and mix to form a dough.
Set aside 1/3 of the dough. Using your hands, press remaining dough into prepared tin to line base and about 2cm up side.
Spread fruit evenly over dough base. Top fruit with free-form pinches of reserved dough, leaving a space in the middle.
Sprinkle pie with extra brown sugar and bake for 30-40 minutes or until light golden. Allow to cool a little before transferring to a serving plate.
Dust lightly with icing sugar, if desired. Serve with cream or ice-cream.