ARE they actually molting? Or is it just that you think it is time for their scheduled molt? (which is possible, but is more likely to wait til later in the summer or early fall).
If they are actually molting, it may well be another month or more before production picks up. You can up their protein intake to help, but there is only so much you can do.
If they are NOT molting, it would still be worth giving them some extra protein, see if that helps. Also make sure their free-choice oystershell or eggshell tin is kept topped up, as calcium depletion (even if they're fed layer feed) can affect egg production somewhat too.
For extra protein sources, most people would use things like feeding some of their eggs back to them (cooked and mashed up first!) or scraps of cooked meat from the kitchen (e.g. freezerburned bits); seeds, nuts or cooked dry-beans/peas have some reasonable protein although not as much as eggs or meat; or you could catch bugs from them, although be aware that will increase their exposure to internal parasites;
It is possible though that they are getting *ready* to molt, in which case, again, there is only so much you can do. They're living creatures, they don't keep a totally regular even schedule
Good luck, have fun,
Pat