Plus, we get the backstory on how another of McKellar's passions led the star and Hallmark to east Tennessee in the first place.

By Rebecca Angel Baer
Dolly Parton and Danica McKellar Christmas at Dollywood
Credit: ©2019 Crown Media United States LLC/Curtis Hilbun

When we first found out that our favorite TV network was teaming up with the legendary Dolly Parton, we were simply beside ourselves with holiday glee. And now, the day has finally arrived. Christmas at Dollywood premieres this Sunday night on the Hallmark Channel. Ahead of the big debut, Hallmark star and veteran of the Countdown to Christmas franchise, Danica McKellar spoke with Southern Living to share some behind the scenes secrets.

For starters, this whole blissful partnership between Hallmark, Dolly Parton, and Dollywood can be traced back to McKellar herself. You may or may not know that after she won America’s hearts as Winnie Cooper in the iconic TV series, The Wonder Years, McKellar took time off from acting and earned a degree in mathematics from UCLA. While she’s returned to our TV screens, the woman of many admirable talents has also become a celebrated author, writing nine books aimed at all ages to make math more fun and approachable. Including a brand-new title, perfect for your little ones’ holiday present list, Bathtime Mathtime: Shapes.

It just so happens that one of these books was the inspiration for Christmas at Dollywood. “Goodnight Numbers, was selected for the Imagination Library two years ago and it was after going to an event to the Imagination Library that I had a meeting with the head of programming at Hallmark and she asked me where I thought it would be fun to do my next Christmas movie,” McKellar recounted. She said that she was told the network was brainstorming for new and interesting locations for the following year’s Christmas movies.

“I’d just come back from this event and I said, well, how about Christmas at Dollywood? And she was like, ‘I love it!’ So, I executive produced this and it’s all because of one of my books getting into the Imagination Library.” If you keep your eyes peeled, this very book will make a cameo appearance in the movie.

As McKellar had suggested, filming took place at Dollywood and production occurred when the park was closed to the public. “They close down the park for a week every year to put up all the Christmas lights. You know, 6 million Christmas lights. Absolutely incredible,” McKellar said Now we know how they transform the park into a winter wonderland.

She also said that when the park re-opened, the whole cast had the chance to just go enjoy it like tourists and she took her mom and son and they had a blast. “Dollywood is such a magical place. I love it. After getting to know Dolly Parton a little bit it’s no surprise that her park would be so wonderful.”

Speaking of getting to know Dolly, McKellar shared a little about what it was like to work with one of the most legendry icons of all time. “Everybody loves Dolly Parton and for good reason. She’s just the most wonderful human being and she doesn’t disappoint. I’ve said this a few times now but whoever said never meet your idols never met Dolly Parton…{she} greets everyone with grace and humility and goes out of her way and yet it seems effortless to make everyone around her feel good about themselves.”

On a recent Facebook Live video, McKellar shared a secret pro-tip she discovered from the Smoky Mountain songbird. “So, Dolly Parton wears wigs, right? So, this wig she was wearing, I couldn’t figure out where her microphone was. Because our microphone packs, you know you have to wear them somewhere on your body and they’re usually in the low of your back, or a thigh pack or whatever. She was wearing this skin-tight, silver-sequined outfit. I’m thinking, I figured she must have put it down her bra, I don’t know. Where’s the microphone pack? And then the hairstylist said she was fixing her hair and she hit something hard in the back of the wig. Her microphone pack was attached to the wig, underneath the hair in the back. Hilarious.” Well, now we all know!

In Christmas at Dollywood, McKellar’s character is a NYC-based event planner who finds herself back home in east Tennessee with the daunting but exciting task of planning the 30th Anniversary of A Smoky Mountain Christmas. Of course, she first seems to butt heads with the director of operations, played by Niall Matter, but as it often does, love finds a way to make it all right. And, as McKellar recounted to us, “Dolly Parton at one point says, ‘Don’t y’all just love a happy ending?’ So there you go. Straight from Dolly.”

WATCH: Alert: The Entire Schedule of New Hallmark Christmas Movies is Out Today

Be sure to tune in Sunday, December 8 at 8PM/7PM CST to the Hallmark Channel.