Preheat oven to 180C/160C fan forced.
Place the apple, rhubarb, sugar and lemon/lime juice in a saucepan over low heat. Cook, stirring occasionally, for 2 minutes or until sugar dissolves.
Cover and cook, stirring occasionally, for 8 minutes or until apple is starting to soften. Transfer to a smallish baking dish.
Set aside to cool for 5 minutes.
Meanwhile, for the crumble mixture, combine the coconut sugar, almond meal, shredded coconut, rice flour, buckwheat flour and mixed spice in a small bowl.
Add the coconut oil and use your fingertips to rub into the coconut mixture until mixture resembles coarse breadcrumbs. Stir in the flaked almonds. Sprinkle crumble over the apple mixture. Add extra Almonds on the top
Bake for 20-25 minutes or until golden. Serve with fruits of choice like some berries and yoghurt.