The other Selcuk Mosque, the Hacı Şeref Cami. Since the Selcuks conquered the city in 1071 and the city was invaded my the Mongols in 1260 - and again at the end of the 14th century, that gives some indication of its date.

As you can see here much of the mosque, including the base of its minaret, was incorporated in a larger construction, as a result the interior is a bit weird.