Toppings cook before the base

Affects quality

A top-heavy heat imbalance, usually solved by better preheating the bottom surface.

Ask yourself

#1
Top heat dominant relative to bottom heat
Generally accepted
Some ovens, particularly with a strong broiler element, cook the top faster than a cold or under-preheated base can catch up.

The same symptom has different answers on different equipment. Each branch below states how to tell whether it is yours.

Pizza on a BBQGenerally accepted
How you would know: On a BBQ with the lid down, the cheese is browned and the base is still pale and soft.
The pizza is on the indirect zone with no preheated surface under it. Convected air under the lid cooks the top perfectly well, but with nothing hot beneath, the base only gets air too.
Do now: Move the pizza briefly over the hotter zone to colour the base, watching it continuously — this takes seconds, not minutes.
Change next time: Add a properly preheated stone over the indirect zone, or cook directly on the bars for a thin pizza where direct contact is the point.

Move the pizza to a lower rack, or cover loosely with foil to protect the top while the base finishes

Preheat the baking surface thoroughly so bottom and top heat are more balanced

Guides that treat this as an outcome to improve, an environment to work with, or a flavour to understand, rather than only a problem to fix.