Not really a cake that I know of...here is a link to some bunny biscuit recipes. I suppose you could make them into a cake shape or something like the giant cookies humans sometimes get. Maybe write his name on it with fruitspread or pumpkin....
For Cinnabun's birthday, I baked a great big cake every year! It always looked different, the first year it was a big carrot, the next a heart, then a bunny, etc. My family ate the cake and Cinny got extra bunny treats that day and new toys :biggrin2: