Fruity Crumble Slice

I'm currently experiencing a slow Sunday.  The weather is warm and has put me into a sleepy and slow state.  I feel like this is the perfect home-made treat to nibble on with friends and family who pass by.

Ingredients
3/4 cup self-raising flour
3/4 cup plain flour
1 cup desiccated coconut
200g unsalted butter
50g unsalted butter, extra, for crumble
3/4 cup soft brown sugar
410g tinned pie apples
40g rolled oats
40g sultanas
1/4 tsp ground cinnamon

Method
Preheat the oven to 180 degrees (fan-forced) and grease and line a 27 x 18cm shallow rectangular baking tin.  In a bowl, sift the flours and combine; add the coconut.  Combine 200g of butter along with the sugar in a saucepan, on low heat until the butter melts.  Remove from heat and pour into the flour mixture.  Using a wooden spoon, stir until well combined.  Reserve 1 cup of the mixture.  Press the remaining mixture into the prepared tin.  It may look as though you don't have enough, but it will press out to form a thin base. Bake for 10 minutes and leave to cool completely.  Spread the apple pieces (you can chop them smaller if needed) over the base.  The base won't be entirely covered (depending on your apple chunk size).  Combine the reserved 1 cup mixture with the 50g of butter, the oats and the sultanas.  Using your fingertips, crumble this mixture over the apple. Dust with cinnamon.  Bake for 20 minutes, or until crumble is golden brown.  Cool, lift from tin, and cut into squares.  Store for 2 days in container, or leave in fridge and watch it disappear quickly.  Serve alone as a slice; or warm it up and eat along with custard.