There was a YouTube video a while back of possibly some Norwegians? that tried a cookie plane if I remember correctly. The engine pulled the nose off on throttle up.
Fruit leather is a possibility for wing surfacing. It is pretty tough. I think partial edibility is the best you may do. You really need a strong airframe at least. I can see an edible quad as a real possibility. A round loaf of bread with a stick frame through it. Even a flying cream pie quad.
The main problem would be weight, bet you could use a combination of bread sticks, rice paper or maybe some sushi seaweed, dry spaghetti and maybe some wafers