Snorlax's best friend is trick room, with 30 base speed, 160 HP, and 110 attack, so here is a trick room set.
0 Speed
Brave/252 HP/252 Attack

Double-Edge and Return are it's main STAB attacks, with Double-Edge working well with it's 160 base HP. Earthquake hits Rock and Steel types, with crunch handling ghost. ZenHeadbutt hits fighting types for super effective damage, since fighting type moves are the only ones that hit super effectively against normal types.

In a double battle, trick room won't need a swap out, so you can take time to set up. Curse and Gluttony/BellyDrum work well, and stockpile can boost both defenses.

In a set without trick room, counter might do some good damage with high HP and low defense, but the problem is finding which move to replace, since moves that usually aren't important for the plan provide STAB or coverage.