Earlier in the day, Dewan shared an inspirational message of her own to commemorate her special day.
"You have made very deep promises between your Soul and your Self. Now is the time to carve your place into the memory of this planet earth and serve this promise," the quote, written by Yogi Bhajan, read. "May your journey complete its way to your destiny. And may you understand the preciousness of your own life."
It's been a whirlwind year for Dewan, who announced in April that she and Channing Tatum were separating after eight years of marriage. Since the split, Tatum has moved on with singer Jessie J, while Dewan has been dating the Tony-winning actor.
A source confirmed to ET that Dewan and Kazee, 43, were a "new" pair in October, a few days before they were photographed together in public for the first time. The two were spotted holding hands while out and about near Palm Springs, California, and haven't been shy about displaying their affection for each other since then.
Kazee has even started leaving flirty messages on Dewan's Instagram posts. "Swooooooooon," Kazee commented on the former World of Dance host's recent black-and-white selfie.
And when Dewan asked fans "Have you found your favorite yet?" -- referring to the comfy pieces from her new Danskin collection -- Kazee couldn't help himself from weighing in. "Yes. I have," he wrote.
When ET spoke with Dewan last month at the 2018 Baby2Baby Gala, she played coy about her new boyfriend but did admit that she's "very happy."