Help needed concerning cat safe/unsafe ingredients

[Chicklet]

I started a small home bakery,
Was mostly on dogs, as I don't know a whole lot about whats safe for cats and whats not,
Problem is, I have been having people request cat birthday cakes,
So now I feel I need to offer a kitty cake,
Can anyone give me some details on what is not safe for cats and what is,
or direct me to a good website that pertains to this information,

Also if anyone has any good kitty cake recipes that does not include Store bought dog or kitty food, no babyfood & no milk products

Thanks for any help on this matter