Ariana Grande -- I Can Make You Hot ... With My Chocolate (PHOTO)

Ariana Grande is an Oval-teen heartthrob ... delivering piping hot chocolate to her freezing fans.

Grande is in London where she performed at Tuesday night's Victoria's Secret Fashion Show. Her fans are camped outside The Langham Hotel and it is COLD.

Ariana sent down the hot chocolate to warm the throngs ... and they got a signed cup for their support.