A320 Captain reported a loss of control event during landing at approximately 100 ft. AGL when jet blast from an aircraft departing a nearby runway was encountered. Aircraft control was regained and the flight continued to landing.

Narrative

The event occurred at in the landing phase at approximately XA20 local ZZZ time. Other than the flight being operated late due to ZZZ1 congestion and delays; the flight was uneventful up until this event. I was the PF during the incident. ZZZ approach vectored us to join the Runway XX ILS final approach course; and we intercepted as planned. Subsequently cleared for the ILS XX approach; handed off to ZZZ Tower and cleared to land on Runway XX. We flew a stabilized approach without incident. Upon the 500 Ft Stable callout; I noticed in my peripheral vision a large aircraft (which turned out to be a A-350) holding in position on Runway YYR. I do not recall hearing a takeoff clearance for this aircraft; as the tower may have been in a 'split operation'. Winds were reported to be approximately 030/15G25. Evidently the A-350 had been cleared for takeoff; unbeknownst to me or my First Officer. At approximately 100 feet AGL; significant turbulence/jet blast was encountered with a brief period of loss of aircraft control. Full left sidestick deflection was made with the aircraft still rolling right due to the jet blast. The event subsided as quickly as it began; with aircraft control being regained and a normal touchdown occurred within the touchdown zone; slightly right of centerline. An inquiry was made after touchdown and tower stated that the A-350 had indeed been cleared for takeoff. We subsequently cleared the runway and taxied to the gate without incident. Upon reaching the gate; I made a phone call to the tower supervisor; and he was very apologetic for the incident and was going to look into the event.