Most baked goods should be rattie-safe. However you'd want them to be fairly low in protein, and, if they are to be regular snacks, low fat and low sugar. Also, things like peanuts could possibly be a choking hazard. Chocolate isn't recommended, though tiny bits of dark chocolate can be okay. Here's the forbidden foods list: http://www.petratscanada.com/forbidden_foods.htm
I know some people make things like carrot cake cupcakes with cream cheese frosting for birthday cakes.
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