Preheat the oven to 180°C
Combine the flour, baking powder, butter, sugar and ground cinnamon if using in a food processor and process until mixture resembles fine breadcrumbs.
Add the lightly beaten eggs and process until the dough just comes together.
Divide the dough into 3 and cover with cling wrap and leave to rest in the fridge for at least 30 mins
Remove 2 of the dough pieces from the fridge and roll out each dough fairly thin and using a 7cm round cutter cut out 18 discs and press into individual tart cases.
Prick the pastry all over with a fork and line the unbaked pastry shells with parchment paper or aluminum foil. Fill tart pans with pie weights, rice, or beans, making sure the weights are to the top of the pan and evenly distributed over the entire surface and bake in the oven for approximately 5 minutes or until the pastry has started to turn a light golden colour.
Remove from the oven and discard the pie weights and fill each case approximately 2/3 full with the cooled apple mixture.
Grate the remaining dough over each of the apple pies until completely covered.
Place back into the oven for approximately 15 minutes or until the crumble has turned slightly golden.
Remove the pies from the oven and leave to cool slightly.
Pop the pies out of the cases and serve with custard or ice-cream