Frozen Perfection

This is not true, for the same reason you can't bake a batch of cookies at 2300 degrees for 1 minute instead of 230 degrees for 10 minutes. I imagine delivering the amount of heat required to bake a pizza in the microseconds of a nuclear explosion would vaporize a substantial part of the explosion-facing side of the pizza while leaving the back frozen.
- What if it's just enough to set the supermarket on fire and the cooler having enough insulation to have the perfect heat for baking?
  
  Hmm, that might work. You don't need a nuclear explosion to set a supermarket on fire so it would be a lot easier to test!
- What if the pizza was being rotated perfectly on a 360° gimbal at the same frequency as the microwaves generated? Hypothetically that is of course
  
  I think spinning the pizza at relativistic speeds only causes more problems. Household microwaves run at 2.45 GHz, and at 2.45 billion revolutions per second a 3.9cm diameter pizza would have an edge velocity of the speed of light (ignoring relativity, which I'm sure does not make things better).
- maybe they arent actually close to the explosion and just get cooked by radiation?
  
  If you're thinking of the neutron and gamma radiation emitted, that happens on an even shorter time scale than the thermal radiation (nanoseconds IIRC) and is absorbed poorly in comparison by a pizza.
- We need a material in between pizza and nuke that absorbs the heat and then gives it off at a slower rate
  
  That sounds like a billion dollar idea!

So are the potential customers, though.
- I dunno, some of them might suddenly have a great deal of potential

See, to all you doubters, you didn't pay enough attention to the Hulk
See, what happens is that the pizza gets hit with the exact dose of gamma needed to kick start the transformation into Pizzulk. Then, the bottomless rage of pineapple haters fills it up, and cooks it from the inside out

If only for a moment..