1/4 oatmeal (some sort of flavored oatmeal works best, I'm told, but I did it with plain, and the kids ate it just fine).
1/4 unsweetened applesauce
1 banana if you want, or a few chocolate chips if you prefer. Probably not the chocolate chips if you are doing an apple flavored oatmeal, but if you want, go for it.
Mix well in a mug, microwave for 3 minutes and let sit for 30 seconds. I flipped this onto a plate so I could wash the mug right away, and it cleaned really easily.
High protein and long burning carbs make it diabetic friendly as well (although the applesauce is a bit problematic, but I think the others outweigh it). Its not perfect, but it will suffice when what you really want is a giant cinnamon streusel muffin from the bakery with the big sugar pieces on top that make you remember that those people who say nothing tastes as good as skinny feels are lying to themselves and the world.