Yikes. I imagine walking in to find that and feeling very frustrated, overwhelmed, disappointed and angry.
I can only tell you what I imagine I would do. First, I'd remind myself that my kids weren't trying to be malicious, but were having fun--and what a sensory experience that must have been! They are little, and really don't think about consequences like we adults do, and can't control their impulses like we adults do. Second, I'd talk to my kids, tell them how I feel about that mess and the wasted food, and tell them we need to make sure that doesn't happen again. Third, we'd clean up together. I think this is really the only natural consequence aside from my obvious disapproval/unhappiness. Finally, I'd make a plan as to how to avoid that ever happening again--putting items like that where they can't be reached, giving them time to play with such items while supervised (and in the kitchen or outside), making sure that either I am not asleep while they are up or that they have things to occupy them while I sleep that are not so messy (and possibly containing them in a safe area while I sleep, with a gate), or whatever other solution I could come up with. I'd likely involve the children in coming up with a solution to prevent that from happening again, asking them for ideas. This is the same process I've used when any of my children have done their toddler thing of pouring out cereal/other single item onto the floor-and while simply pouring out cereal or anther single item is obviously on a much smaller scale, I think it's basically the same issue. This has worked for us, I've never had a child repeat dumping, though I am wary of taking credit for that (perhaps they just got it out of their systems in that one episode). I think a process like this is much more likely to teach them what I want them to learn than coming up with other consequences would be, though I too would feel the urge to come up with a list of unpleasant consequences. That is just what I would do.
I hope your day gets better. And I hope you have a shop-vac, or can rent/borrow one.