While we are on the subject of beetroot I would highly recommend this Can't Be Beet Chocolate Cake. It is super moist and has a delicious earthy chocolate taste. And it's low fat! The Forest in Brisbane used to have a cake that was similar (which was gluten free but not low fat) so it made me a little homesick.
I made it without the sauce simply because it is so delicious I didn't think it needed it. But I'm sure it would taste great with maybe a beetroot glaze or a berry frosting.
EDIT: Since first posting this I've had a lot of people contact me about how weird they think chocolate beetroot cake is. It's very much not weird! If you are in Brisbane you all need to go to The Forest in West End and try some! Or cook this one! It really is just delicious.