I'm training my brother's Chansey and It needs more happiness. Does feeding your Pokemon Poffins raise it's happiness?
According to this chart, No.
No, they don't
>Poffins are the successors of Pokéblocks in the sense that they raise either the Beauty, Tough, Cute, Cool, or Smart condition of a Pokémon in a Contest, when fed to the Pokémon. -Bulbepedia
Nope. But these do:
>-Having the Pokémon in your party -Giving it Vitamins -Giving it a massage in Pallet Town, Goldenrod City, Veilstone City or Ribbon Syndicate -Giving it Certain Berries -Gaining a Level - Serebii