I found a recipe online that required making cookie dough from scratch and then wrapping the cookie dough in wax paper and refrigerating for 2 hours. I made the cookie dough and it was way too crumbly and dry for me to be able to put it in one piece in the wax paper without it falling apart. What should I do?
Part of what is going to happen during the resting period is that the moisture is going to more evenly distribute throughout your dough, and begin hydrating the starches, so that they it will become more cohesive.
Assuming there is enough moisture present, you just need to give it time. 2 hours may not be enough time--4 would be better. Overnight would certainly be good.
If there is insufficient water, carefully distributing a few drops (maybe a tablespoon or two, maximum) before refrigerating will help, but you need to be sure this is the case. Try letting it rest for four hours as is, and if it is still crumbly, then add some water.
Lastly, you may find that plastic wrap (sometimes called film wrap) may be easier to use than wax paper. You want to roll your dough tightly, holding it together while it hydrates. Normally, the two shapes that would be used would be a log (for sliced cookies) or a disk (for cookies that will be rolled out).