Grace VanderWaal is living every 12-year-old's dream. She just won the $1 million grand prize on the 11th season of America's Got Talent, which earned her shout-outs from Katy Perry and Reese Witherspoon and a giant bouquet of congrats flowers from one of her inspirations, Taylor Swift. She's also signed to the same label as Beyoncé and Adele, and pledged to donate some of her prize money to charity after spending some of it on a treehouse in her backyard thanks to the folks behind Treehouse Masters.

10 Times Taylor Swift & 'America's Got Talent' Winner Grace VanderWaal Were Totally #Twinning

That's a lot of dreams coming true in one week. But after reading last week that singer/songwriter Jason Mraz is VanderWaal's favorite artist -- and the one she would most like to collaborate with -- well, Billboard had an idea.

OMG!!! I love you!!! Thank you so much ------ https://t.co/ttnNA8Cvwq — Grace VanderWaal (@GraceVanderWaal) September 15, 2016

With her parents' permission, we got Grace on the phone to talk about her career plans and how things have been going since her big win. Oh, and we had Mraz on the line to surprise her. Check out the video below of the priceless moment:

Before the two chatted, Billboard asked VanderWaal about last week's tweet from Mraz and how it made her feel. "Jason Mraz tweeted me too!" she said excitedly. "I love him sooo much, he really inspires my writing sound. I think we have similar styles. He's one of my favorite artists." Once Mraz introduced himself VanderWaal squealed "... MRAZ! Oh my GOD!!!" He thanked her for the kind words and recounted how he saw her drop his name in an article and decided to look her up and listen to her songs while following her journey on the show.

"I just think what you're doing is fantastic," he said. "I think there's something deep inside of you that you're allowing to come through and you're doing it well." Grace, still a bit shocked, said, "thank you so much!" He appreciated all her kind words and let her know how stoked he is as one of her newest fans for her win. "Thank you sooo much!!!" she said.

Asked to give his young protége some advice, Mraz said he liked hearing that VanderWaal planned to take things slow. "Go with your gut," he advised her. "If there's something in your gut that says, 'this is not the right thing to do,' then don't do it. But if your gut is telling you, 'this is going to bring me joy... singing this song every day for the rest of my life is going to bring me joy,' then follow that. It's really about listening to yourself and staying true to yourself so that your music can thrive and so that you can live your dream."

It's not often you get to talk to your heroes, so when VanderWaal was given the chance to say something to Mraz or give some key career advice, she said, "no, you're doing great!" Then, on second thought, she added, "but can I say I do miss when you had that long-ish hair! That was so cool! And you cut it!" Mraz laughed, telling Grace she was the only person who liked that look.

VanderWaal spoke to Billboard just before taping an appearance on The Ellen DeGeneres Show, and when asked if the people in her hometown of Suffern, New York, knew who she was now, she said they definitely do. "Everyone has been watching the show in my hometown," she said. Even those kids who were kind of mean to her and inspired some of the heartbreaking original songs about not fitting in that she performed on AGT?

"A lot of people are a lot more like, 'please hang out with me... we never talk... we should talk more,' even people who were really mean to me. But I know who my true friends are." And while she's been trying to write some new songs about her world-changing experience, the ukulele-strumming tween has mostly been decompressing and relaxing after her whirlwind ride. "I've been sleeping like... have you ever heard that koala's sleep for, like, 28 hours or something? Well, I have been sleeping like a koala!"

At the end of their call, Mraz offered VanderWaal the thing she wanted the most: a chance to collaborate. The Jason Mraz Foundation runs a non-profit arts program for disabled and typically-abled students in his native Richmond, Virginia, called Live Art that hosts a one-night only concert with veteran musicians and actors at the end of the school year. The event has featured appearances by Sara Bareilles, k.d. lang, Keb Mo, Christina Perri and Chris Stills over the years, and Mraz said he'd love for VanderWaal to participate next summer.

"I'd love to invite you to join me on that next summer and perhaps we could sing a duet there, or we could write something original for the show," Mraz said. "YES!! YES!! I'll be there!!" VanderWaal responded.