I wanted to know how to offer Namaaz with Hadiya to any of the Masoomeen. Do I make the Niyyat at the start of my Salaat and then offer the Namaaz as usual with 1x Surah Fatiha and 3X Surah Ikhlas at the end with the intention of Sawaab?

There is no specific method has discussed regarding Namaz e Hadiya for Aimmah (a.s) and normally it has said we can pray as Fajr prayer. Regarding number of rakats, we have that for example hadiya ke namaz for Holy Prophet (saww) on Friday’s has 8 rakats (4 sets of 2 Rakat) then first four Rakat is for Holy Prophet then second four Rakats for Lady Fatma (s.a) then on Saturday 4 (2×2)rakats Hadiya for Ali (a.s) and then everyday 4 Rakat Hadiya for all Aimmah (a.s) etc then at the end short Dua but in all these Namaz there has not been mentioned any special Surah’s or method rather one can say all these Namaz as morning Fajr Prayer.