Hi Ed and David,
Interesting topic, thanks!
At the West Point Museum, I snapped this pic of a 19th century Filipino hand cannon. Kindly note that in its description, the design supposedly dates back to the 15th century.
We will note also that the Filipino hand cannon's design is very much similar to one of the pics David posted above (and posted again below).
The first Europeans landed in the Philippines in the 1500s (starting with Ferdinand Magellan in 1521). Assuming that the hand cannon design originated from Europe, then the usage of the hand cannon by Filipinos may have started as early the mid-1500s.
On the other hand since gunpowder must have first been invented in China, it may also be possible that the development of the hand cannon of the type pictured below was Asian in origin.
The other type of hand cannon that was extensively used in southern Philippines, Malaysia, and Indonesia was the
lantaka. Its photo appears at the bottom, below.
Regards.