Usually I’ve been asked about how to run a cron task manually. A cron task defined in Magento is not anything else than a function that belongs to a model that is loaded and executed.
For example, we have this cron task on a config.xml file of a specific module:
It’s easy to identify the model and function that is being loaded and executed as it is inside the <model> tags. The model that is being loaded is sap/cron_sync_nonimage, and the function inside that model that is being executed is run.