I'm particularly interested in exploration on the topic from the lens of comparative religion. I am fascinated by the links between Mithras, Mithra, Mitra, and Maitreya.
Two of the most preeminent contemporary scholars on Mithraism are Manfred Clauss and Richard Gordon, Clauss' Der Kult des Mithras has been translated by Gordon and is available in English as "The Cult of Roman Mithras: The God and his Mysteries (New York 2000). It has a strong focus on the archeological and iconographic evidence there is for the cult and its rituals, and uses this to contrast the more theological approach by Cumont that has dominated scholarship and popular interpretation for quite some time.
I think it is a very good book as an introduction, and he devotes two chapters to both the background in Persian and Hellenistic Mithras, as well as the development of the very Roman cult that came to prominence in the 2nd and 3rd chapter. Because of its focus on the concretely available evidence, I think he is able to illustrate the topic very well and make strong points.
For Gordon, who has a differing viewpoint to Clauss in some regards, especially concerning ritual and the structure of the Cultic community, there's a rather recent article of his in the Blackwell Companion to Zoroastrianism, that might interest you: R. Gordon, From Mithra to Roman Mithras, in: M. Stausberg et al. (eds.), The Wiley Blackwell Companion to Zoroastrianism (Chichester 2015), 451-455.
Roger Beck, The Religion of the Mithras Cult in the Roman Empire: Mysteries of the Unconquered Sun (Oxford 2006) is also a pretty good depiction, using theoretical models taken from the social sciences, but because of that it focuses a lot more on the social aspects of Mithraism, on ritual practices and its symbolic system, which might be of interest to you.
There's also this article from the Zeitschrift für Religionswissenschaft which focuses on the connections between Roman and Persian Mithras from the perspective of comparative religion, but it's in German and behind a paywall: