I have a cathedral style ceiling and I putting recessed can lights in. Im wondering what type of insulation I can get behind the can light so that the coldness of the roof and the warmth of the can light won't create any moisture. There is only 1-2 inches between the top of the lights and the roof. What can I use or is it going to be a problem

If the fixture is IC rated you can put any insulation around it, check to make sure you have the right kind of fixture and read the manufacturers information.

Recessed Lighting Guide Recessed Lighting Tips Help and Advice

Contact the manufacturer and stop looking for answers on the internet. Are you going to hold us responsible if your lights catch fire because you wrapped them in insulation? A simple call to the supplier or manufacturer should sort this out.

Can lights have "hoods" that can be put over them. Some come with them, some do not. If your insulation covers the can light, it will get too hot and shut off. The way to insulate around can lights is to put the insulation as close as you want to it, but do not cover it due to fire or obsessive turning off.