Last year my daughter's 5th grade class made those cookie dough jars. The kind full of flour, sugar, baking powder and chips, etc. Then you include a card about adding butter and vanilla. They did this assembly line style with parent help.
That is tough. I usually look on pinterest to try and find some ideas. I saw a cute idea with the small tiles and making them into coasters. You use modge poge and such.
I have done these with older kids and they seemed to enjoy it. It is definitely a craft for older kids, younger kids don't have the patience or the ability to bunch the tissue paper tightly enough to make it work, at least the ones I did it with. They also have a similar candy candy kit. The only complaint in the reviews is not enough tissue paper, personally, I have not had this problem, but it could be easily remedied by just cutting extra tissue paper yourself.
My son's class used new tube socks, filled them with rice, tied off a head and added a little felt hat, scarf, eyes, nose etc to make a cute little bean bag snowman. They loved that. They also made hot cocoa mix to take home.
On my teacher blog I have a post about how to make a gorgeous 3-D snowflake. It is perfect if you need an easy craft with just a few basic supplies.
If you want to do something more you could have them make graham cracker gingerbread houses. Make the houses one class period and have them decorate the second day.
5th grade is tough for crafts. I know when I was class parent the kids didn't want to do anything at their holiday party other than eat and just hang out with each other. The other class mom had brought some type of craft but most kids didn't do it.