From the web I gathered: "Located at the junction of Abdal Street, Tahal Street and Gül Avenue, the mosque was built by Başçı Ibrahim Efendi in remembrance of Abdal Mehmed, who was a well-known Sufi of the Murad II. era. On top of the rectangular-planned mosque, there are two oval domes. Next to the mosque are a tomb and a water fountain. The mosque has largely been repaired by the Bursa Association of Antique Lovers in 1955."

How the mosque came into being is an interesting story:
Başçı Ibrahim Efendi had been the favourite pupil of the Sufi-master Abdal Mehmed, and it was told that he was blessed with great wealth after his master had said a special prayer in that intention. Başçı Ibrahim used his wealth to commission a number of public buildings, including two mosques, a hamam, a graveyard and a mausoleum for himself. In building the mosque in remembrance of Abdal Mehmed, he shared (in some way) his opulence with his former teacher – what the latter surely would have refused, if he had still been alive…

On the picture: the prayer hall (8 x 15 m) with the minber (pulpit) and the mihrab (prayer niche), which is decorated with glazed tiles from Kütahya.

Correspondent: J.M.Criel, Antwerpen.
Source: ‘Vakıf Abideler ve eski Eserler (volume III)’ - Vakıflar Genel Müdürlüğü, Ankara 1983