Blackberry & apple crumble cake

So a few weeks ago me and a few others at work picked blackberries in the lane near our office, I therefore ended up with 800g of frozen blackberries so started looking for recipes to use them in! I'll admit, I'm not a huge fan of warm fruit or indeed fruit in cakes but this recipe sounded nice and I thought I'd just make it for the people in my office. I found it on the BBC Good Good website and although the reviews are mixed I didn't find it too difficult to make after a bit of logical re-arranging to the recipe! Anyway, here's the finished product: