Baking and taking cake

On Friday I'm finally making it to an outdoor film screening. As well as an unfeasibly large pile of warm clothes, I'm baking and taking a blackberry crumble cake to enjoy with my oldest friend and her daughters. Like many of my baking sessions, this will involve going a bit freestyle. Although I haven't been making cakes for very long, I'm confident enough in my cooking to alter recipes to suit me.
The recipe I used is based on one from Hedgewizard's diary blog. I think I've made it before with apples as described, but now it's customised. Now I just have to avoid eating it before Friday...