What are the keys to leopard-spotting pizza crust?
I would guess the secret is having your dough be irregularly textured.  

The spots have to be cooking, and scorching, before the rest of the crust is even browning.  You might be able to achieve this by deliberately texturing your dough, but I expect the original reason was gas bubbles trapped just under the surface of the dough, which blistered and burned quickly due to thinness of the dough and heating faster than the rest of the crust.  

So how to get this blistering?  you would need very well developed gluten, to hold thin, fragile bubbles right on the surface.  You would need very gentle handling for the crust - resting and raising again might let your dough puff up again from rougher handling, but it would probably tend to be smaller bubbles and even puffing, not great surface ones.  And you would need very active yeast, to raise great bubbles on the surface.

How exactly you get these factors will depend on your recipe and your tolerance.  You might make your dough from a preferment or a series of them, so the yeasts have time to develop better and will be more active, or you might use more yeast in general to make the dough rise more quickly to form bigger, irregular bubbles instead of small even ones.  Kneading your dough better for good gluten development might help it trap the gas bubbles, even right on the surface.  You could try long, cold rises for your dough, which should develop gluten and yeast activity better than shorter, warm rises.  You might handle your dough very carefully around the edges, using your hands to stretch rather than a rolling pin or similar, to keep as much air trapped in the crust as possible.  

You might just cheat, and pinch up knobs, slice flaps, or inject air into bubbles (with a syringe, maybe, I know they're available for injecting marinades) to artificially texture the surface of your crust with thinner or upraised areas that will brown and blacken quickly - which will get your your dark spots with probably less effort than reworking your dough texture, but may not get as much of the texture or taste you're looking for, that happens to go with your spots.  It's all up to you.