This study explored over 200 journals and a content-focussed research repository to investigate the occurrence of research on the Big Questions in the field of astronomy education research (AER), focussing on Cosmology and Religion. Using both qualitative and quantitative techniques, 151 articles were selected and analysed. Our results reveal that AER in the context of cosmology has increased vastly over the past few decades. Despite this, there is still a lack of research exploring the various constructs especially focussing on teacher education, curriculum, misconceptions, and the common ground between cosmology and religion. Our textual analysis of the articles revealed 16 themes, which could be encompassed into two overarching themes of "Science" and the "Universe". We used a 13-criteria scoring rubric to analyse the constructs found in the articles. Using our scoring rubric, the top four criteria were Cosmology "Big Questions" ([approximately] 29%), Cosmology Content ([approximately] 22%), the Cosmology Science-Religion Debate ([approximately] 19%), and Cosmology Attitudes ([approximately] 18%). These results hint at a fertile landscape for research into Cosmology Education, and the Cosmology-Religion interface given the ground-breaking advances in modern Cosmology.