Marissa: I loved the cat rescue scene, too. I’m never more in love with my husband than when he’s snuggling our cat. I also loved any scene with Faye in it, because she reminded me of my own Grandma, who I love and miss—and because her life experience gave her a beautiful depth. The surfing scene with Cass and Miguel was a lot of fun to write, too. If I close my eyes, I can visualize the moment they reach for each other’s hands. It’s so perfectly romantic, which is exactly what we wanted this book to be.

How did you come to craft Cass and Charlie’s authentic sisterly push-and-pull dynamic? Did you pull inspiration from your own sibling relationships?

Karma: I have a sister who is only fifteen months younger than me, and we were incredibly close growing up. Due to our closeness in age, we ended up going through many of the same experiences at the same time. Yet despite our similarities, our career paths look quite different—she’s in the medical field and I gravitated to one in the arts. We are similar to Cass and Charlie, I guess, who forged their own paths as adults but remain each other’s touchstone.

Marissa: I have three brothers, no sisters, and Karma and I would often discuss the difference in our sibling dynamic. With my brothers, it’s all pretty straightforward. I appreciate the simplicity, but sometimes long for the deep closeness you can have with a sister. For inspiration with Cass and Charlie, I often looked to my relationships with close friends—and thought a lot about the idea that with a sister, you don’t get to choose each other, but you can choose what kind of relationship you’re going to have.

What is your signature dessert to make (or buy) during the holiday season?

Marissa: We always bake gingerbread cookies and a gingerbread house—although nothing nearly as elaborate as the one on display at Woodburn Breads!

Karma: My family’s Christmas Cake recipe is the one thing I make every holiday season!

This might be a controversial question, but if you were a character in The Holiday Swap, who would you prefer as a romantic interest—Miguel or Jake—and why?

Karma: It is impossible to choose. I adore both Miguel and Jake for different reasons and am smitten with each of them.

Marissa: I feel the same. We fell in love with them both!

Without giving anything away, did you always know how the story would end for Cass and Charlie?

Well, we always knew our twins were getting a happy ending! But for the longest time, we didn’t know exactly what that was going to look like. We had a placeholder for the final chapter that was something along the lines of, “And they all lived happily ever after, smooch! Swoon!” We think what we came up with for the real final chapter is so much better—and that’s all we can say about that.

What’s next for you?

Next up for Maggie Knox is our second holiday romance, All I Want for Christmas, which is set in Nashville, TN, and features a reality singing competition and two competing musicians, Sadie and Max, who dislike each other but are obligated to pretend to be a couple. They have fantastic chemistry on stage, but behind the scenes is another story. Until they find some common ground and things start to heat up! Karma is also working on her next standalone novel, What Wild Women Do, which is a dual narrative story set in the Adirondacks in the 1970s and present day. And Marissa is working on television development for her latest novel, Lucky.