A couple of weeks ago I bought Disney branded Mickey Mouse Chicken nuggets and Mickey Mouse chicken patties (they were bigger then a hamburger bun size) at Target. The patties and nuggets were MM head shaped (so the ears were visible). I've seen Disney themed ravioli too but that was a long time ago and I don't remember where. Just an fyi- of my 2 local Target's only one carries the chicken. So you may want to call and check around first.
Also do you have a Mickey head cookie cutter? You could make cookies or rice krispie treats with it (you could even dip the ears in chocolate maybe add some sprinkles?)
Right now for $1.99 at Walgreens in the Halloween section, they have a Mickey Mouse plastic cookie cutter (smaller then the one you can find in the parks) that comes with orange and black gel frosting. I picked one of these up but we haven't used it yet, so I can't say how it is.
Get some of the plastic reusable straws and put 3 marshmallows on the end and dip them in chocolate and decorate (like the ones you can buy at Goofy's at DTD).
HTH