Menendez Brothers Halloween Plans Include 'It,' Candy Salad, DIY Taffy

The Menendez brothers are on a roll lately with a possible chance at future freedom -- and TMZ has the low-down on what could be their final Halloween in the slammer.

A source within the California Department of Corrections tells TMZ ... Erik and Lyle are all set for a Halloween movie night in the clink, where they’ll likely be cozying up to the OG 1990 version of Stephen King's "IT."

We're told the bros and their cell block buddies at the Richard J. Donovan Correctional Facility in San Diego are whipping up a classic prison treat for the occasion -- "candy salad," which is basically a mixed bag of every candy available in the commissary thrown into one giant bowl.

They’re even going all out with chips, cookies, microwavable popcorn, soda, and some DIY taffy ... made by mixing creamer and Kool-Aid.

In the spirit of Halloween, we're told the Menendez brothers and their crew are getting fancy -- draping a clean bedsheet over the dayroom table to serve as the buffet spread.

It's not just the Menendez brothers' facility getting in on the Halloween party. Prisons across California are spicing things up with mini-fests, family days and “trunk-or-treat” setups -- with staff decorating their car trunks outside and handing out candy to visiting kids and families.