Vanilla Ice says it's "amazing" that Britney Spears is a fan of "Ice, Ice Baby" ... and tells us the footage of Brit jamming out to the song at a recent "X Factor" audition is nothing less than a "classic moment."
"I love it" ... Ice said ... adding, "Simon Cowell giving her a high five? That is AWESOME!"
We posted the footage earlier this week ... Britney got out of her seat at the judge's table to dance and sing along with the lyrics while a contestant performed the 1990 classic during an audition in North Carolina.
Vanilla tells us he's glad his song is still "kicking ass" ... insisting the jam has a "magical connection" to people in their 20s and 30s.
Ice -- who's about to start production on Season 3 of his home renovation show "The Vanilla Ice Project" -- added, "Britney Spears is a legend ... and she rocked out to MY song? That's f**king amazing!"