"She's unbelievably good," YouTube comedian Whitney Avalon says of working with Gellar

Credit: Candace Lauren Ostler

This is not your parents’ Cinderella.

In the latest Princess Rap Battle – a successful YouTube series from actress Whitney Avalon – Sarah Michelle Gellar dons the princess’s iconic blue gown for an epic rap battle against Beauty and the Beast‘s Belle.

“Sarah had posted the first Rap Battle on Twitter, so we knew that she had seen it and that she was a fan,” Avalon tells PEOPLE. “So we thought, ‘How incredible would it be to put her in this gorgeous gown and have her be Cinderella?’ Fortunately, she felt the same way.”

Avalon – who says she grew up in Massachusetts with “Weird Al” Yankovic as her idol – actually got the inspiration for the the first Princess Rap Battle while writing a song for herself.

“I was writing a comedy rap from my own perspective. Because I’m super-pale in real life, it had a line about how ‘I’m white like snow, pale like ale, a porcelain-skinned princess from a fairy-tale,’ ” she says. “Then I just thought, ‘What if it is actually Snow White rapping?’ And it all just flowed from there.”

Avalon and her co-writer/co-producer Steve Gossett have now made four Princess Rap Battle videos – each one taking about six weeks to produce – but Gellar’s involvement has taken the popularity of the series to a whole new level.

“The first one already went pretty seriously viral with 25 million views so far on YouTube and then Sarah signed on and of course that made even more people go, ‘What are these Princess Rap Battle things?’ she says. “I don’t believe Sarah has ever rapped before but she’s unbelievably good. She’s also a lot of fun, and that’s what this is all about at the end of the day.”

Though Avalon admits that the rap battles “are not really made for kids,” the actress hopes her the younger fans can take away an empowering message from her work.

“These are silly, short little videos, but I think there is a message of standing up for yourself and being brave in a world where females are still fighting for equality and power and a voice,” she says. “And it makes me cry with happiness that people are excited about that message.”