Get all your ingredients.
Put your oven on Gas mark 4 to heat up.
Wash your apples and remove any bruises etc.
Cut each one into 4, remove the core and pips and slice.
Place slices into your oven proof dish covering the bottom.
Add your blackberries ontop of the apple slices.
Pour over the water, you can add some sugar if your apples are on the sharp side.
Now make your crumble.
Place the flour, oats, sugar and cinamon in a mixing bowl, stir.
Add your margarine, cut up into the flour, then rub until mixture is evenly mixed.
Mixture should look like this.
Tip your crumble ontop of your apples and blackberries.
Smooth the top and bake in the oven for about 1 hour.
Remove from the oven and serve.