I'm working on a project set in Mongolia in either the late 13th or early 14th century. This is well after the initial conquest, and from the preliminary reading I've done (mostly just wikipedia) it seems that there was a robust bureaucracy in place by this time. They had a "pony express" style courier system, they administered the Silk Road, and it seems that religious freedom was the norm throughout most of the empire and the khanates that it later became. It seems that in general, it was peaceful and prosperous for almost a century.
Anyway, I can't find many resources on this period. There are endless books about the conquests and wars, but seemingly almost nothing about daily life. I want to know how people lived throughout the empire, what kind of values they had. I want to know about their architecture and fashion, and their food, drink, and recreation. I realize that there was probably no single "Mongol culture," given how huge the empire was. But the lack of this information (and the seeming lack of interest in it, compared to the wars) is disappointing, and is really hampering my research for this project. Any help is much appreciated.
You'd probably be interested in the work of Thomas Allsen, in particular his books Commodity and Exchange in the Mongol Empire and Culture and Conquest in Mongol Eurasia. Now, granted, both of these works are around 20 years old now, but they're relatively effective at portraying the breadth of Mongol culture (especially in the Western/Islamic parts of the empire) during the period. George Lane's Daily Life in the Mongol Empire is more recent but less academic—but depending on the depth you need for your project, it might be exactly what you're looking for!
ETA: also, various articles in Christopher Atwood's Encyclopedia of Mongolia and the Mongol Empire (in general an excellent resource if you're interested in that time/place, but, you know, limited by the encyclopedia-article format—can be a good guide to further literature as well).
Now, one issue here is that works like these tend to be done by scholars who have more experience with texts from only a distinct portion of the overall empire—usually Iranists or sinologists. So if there's a particular area of the empire you're interested in, you might want to look for general accounts by scholars who specialize in that region.
The other is that of course the most in-depth information often won't be in general accounts, and you may be better off looking into monographs for each subject instead. For example: Allsen's chapter on Mongol/Islamic textiles in Commodity and Exchange is great, but his treatment of Mongol "cuisine" in Culture and Conquest leaves something to be desired. There you might want to look into, say, the work of Paul D. Buell (especially A Soup for the Qan, a translation and commentary of a Yuan-period Chinese cookbook co-authored with Eugene N. Anderson, but he has a number of articles on Mongol foodways scattered around) or John Masson Smith instead—but it wouldn't really inform any of the other stuff you're looking for, so that's just more work for you!