I am looking for cases (if any) where patients were pronounced dead by doctors and then came back to life. Are there any such cases? I am not looking for cases of near-death experiences.

New York woman found breathing at funeral home after being declared dead.

Word on the street is Jeebus did, after rotting for three days!

It must’ve been a god damned miracle.

I am dubious.

Then, there are dozens of books and movies documenting Vlad Dracula’s un-death.

No doctors though. My mistake. Apologies.

This is a very tricky question because of the 'pronounced dead' element.

Generally, when a doctor pronounces death, it means that there is no further medical intervention. As such, this basically just means we're looking for examples where a doctor was mistaken in their determination of death, not that the person came back after dying.

If we don't concern ourselves with the official declaration of death and just look at the biology, then there are many examples of people being resuscitated from cardiac arrest - it happens every day all across the planet.

Generally, there's a small window after cardiac arrest where the brain still has enough resources to continue without cell death commencing. There's a small window after that period in which cell death may be sufficiently minimal that resuscitation has no lasting side effects. Then there's a small window after that where the brain can still be resuscitated, but some brain damage has occurred. These windows can be extended by keeping the body cool so that cell death is slowed down. Example of this include people falling into very cold water - if you're going to have cardiac arrest but hope to survive it, then there's no better place than in near-freezing water.

3.5 hours here seems to be an outlier:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004494/

I think Spearthrower has nailed it here, pronounced or presumed death is not neccessarily death. To make things more complex death can be called by emergency medical providers in extremus even when the heart still beating in the casualty. In these 'mass casualty events' the 'black' or similar triage code is used for deceased/expectant where the deciding factor is only no spontaneous respirations even when respositioned. I have personally attended a multiple casualty motor vehicle accident where one of the casualties was categorized as black (expectant) due to massive head injury and was left alone for an hour while more promising casualties were attended, once they were stablised I returned to the person and resusitated them succesfully after an hour of classified 'death'/expectant and they were discharged from hospital with minimal disability 6 weeks later.
They on;y seemed to have returned from the dead..

https://www.bbc.com/news/world-latin-america-65886245

Mourners at the funeral of an elderly Ecuadorean woman were startled to discover she was still alive.

Bella Montoya, 76, was declared dead last week following a suspected stroke.

Five hours into her wake on Friday, relatives preparing to change her clothes ahead of the burial found her gasping for air.

Ms Montoya is now back in hospital in intensive care, and Ecuador's health ministry has set up a committee to investigate the incident.

An example, presumably, of a misdiagnosis rather than spontaneous revivification.

I think that’s the measure of it. Once those synapses in the brain disconnect, that’s the end of it.