Hi - yes mollykins, you can add your oatibix to the base. the best way to add orange flavour to the cheescake part is to use the very fine grater to do the zest, and add a little orange juice or orange liqueur such as Cointreau, Triple Sec, Mandarin Napoleon, or Grande Marnier. I would then put orange segments on top, either fresh or tinned (well drained) and just decorate with chocolate shapes. Personally I can't stand chocolate and orange together, i can't understand why people think they go together, but then that's just me. I wouldn't recommend covering a cheesecake in chocolate either, the fat content of the cheese could make the chocolate 'sweat'