Ok so I need some help! my sister inlaw is having an engagement party and she has asked me to make her cake which I am happy to do she has asked me to do something like the attachment - now I know it looks simple enough but how would I go about the branches?

Shan...

Very pretty cake. I think modeling chocolate would be easy, but you coud use fondant, too. Use the image you have for placement of the branches.

I agree with Lapazlady. Modeling chocolate would be the easiest option because you would already have the desired color and it would stick right onto the cake. I just started working with modeling chocolate and I love it.

Whenever I have to make branches like these-I have success with fresh tootsie rolls-candy rolls out into any size branch you need and will stick to icing before it crust.
If icing has crusted-brush branches with clear vanilla using a brush-dampened not dripping wet-to attach branches.
Happy Baking and Decorating,
Chef Angie