Preheat oven to moderate, 180c. Lightly grease and line an 18 x 28cm slice pan with baking paper.
BASE: In a bowl, combine flour, brown sugar and coconut. Blend in butter. Press mixture firmly into prepared pan. Bake for 15-20 minutes until lightly browned. Allow to cool.
FILLING: Spread apple over base. Whisk together cream, eggs and caster sugar. pour over apple. Bake for 20-25 minutes until firm.
TOPPING: In a bowl, combine all the ingredients. Sprinkle evenly over slice. Bake for 12-15 minutes until golden. Allow to cool in pan. Dust with icing sugar and cut into squares to serve.