Congrats are in order for Cooper Hefner and Scarlett Byrne, who just gave birth to a baby daughter named Betsy Rose Hefner.

Cooper told People that he and his wife are “filled with such joy — we couldn’t be happier” about their little “treasure.”

The baby girl is named after his grandmother, Betsy Aldridge-Conrad, who died in July.

“My grandmother meant the world to both Scarlett and I,” says Cooper. “We are overwhelmed with joy to share that our daughter, Betsy Rose Hefner, has arrived. We look forward to being home and spending time together as a family in the days and weeks ahead.”

Cooper is a fellow for the German Marshall Fund, a teacher and board member at Chapman University and board member of such nonprofits as Children of the Night.

Huge congrats!