"It was the best present ever," he tells PEOPLE of the Dec. 22 proposal. "It was the happiest moment of my life."
The couple, who started dating while costarring in the 2008 thriller Prom Night, got engaged in Schaech's hometown of Edgewood, Maryland, where he surprised Kramer with a proposal during their holiday vacation.
Schaech, 40, who was married to Christina Applegate before the two divorced in 2007, says: "I can't wait to make Jana my wife and have a family."
Schaech recently wrapped the film Georgia, opposite Emmanuelle Chriqui.
To view Schaech's romantic marriage proposal, check out his Facebook page.