OurLittleBlessing - the cake is for my DPs Nan's birthday. DPs mum is gluten and lactose intolerant. It's a rainbow patchwork cake so will do trials to make sure it turns out right :-)
I won't need to worry about the cross contamination factor as she's not that sensitive. But thanks for letting me know about it - I had no idea!!
Thanks for all the awesome ideas, I will let you know how it goes :-)
Oh and I'm hoping the inside of the cake will look something like the picture below (the uncooked batter)