I marked Hersheys but peanut M&Ms are really close!
We don't really do trick or treating (too dangerous where I live) but we do have parties for Víspera de Todos los Santos (Víspera de los Muertos)... which is halloween night, eve of the Day of the Dead. We celebrate Dia de los Muertos on the 1st and 2nd November, so halloween is just a head start, lol.
Lots of sugar skulls, membrillo tarts, miniature pan dulce, tiny cakes, chocolate rats, stuff like that. I do sneak in some M&Ms when I can.