Smith popped the question at the Boston Public Garden over the holidays
On New Year’s Day, the cute couple – who first met through church – enjoyed a romantic dinner overlooking the city at the Top of the Hub in Boston.
Afterwards, “we went on a ride in a horse-drawn carriage through downtown that led to the Boston Public Garden,” Smith tells PEOPLE exclusively. “That’s where I knelt on one knee and she said yes!”
Denny, who is a speech language pathologist, has been by Smith’s side since the beginning of his Voice journey.
“I can remember a conversation she and I had three years ago when I turned up the radio as we were driving, and I said ‘I love this song. I would love to sing this on The Voice,'” Smith recalled before the finale of NBC’s singing competition show. “She has been here since the beginning and she’s always expected something like this for me.”
On their spare time, the couple “loves to sing together sometimes,” he adds. “I think she has a beautiful voice. She acts embarrassed and she won’t really sing for me much, but I love her voice and I love listening to her sing.”
“I’m thrilled!” Voice executive producer Mark Burnett told PEOPLE Monday about the engagement. “How you can really judge it is how someone is beaming, full of life. Last night he was just thrilled to have gone home as the winner, gotten engaged to his sweetheart.”
•With reporting by CHRISTINA DUGAN