Here comes the bride -- again! Alyson Hannigan and husband Alexis Denisof have already been married for almost 10 years, but they're so in love with each other that saying "I do" once just isn't enough. On Sunday, July 28, the How I Met Your Mother actress revealed that she and Denisof plan to celebrate their upcoming 10th anniversary with a special vow renewal ceremony.

PHOTOS: Hollywood's hottest married couples

"My hubby @AlexisDenisof surprised me with the most romantic day of my life yesterday!" she tweeted to her 686,000 followers. "Which included another proposal & ring! I said YES!"

The next day, Monday, Hannigan, 39, stepped out in L.A. to get coffee and happily flashed her new bling for photographers. The only thing brighter than the huge, round-cut diamond was her grin.

PHOTOS: Blingy celeb engagement rings

"Now we get to have our kids at this ceremony," she wrote on Twitter. (The former Buffy the Vampire costars are parents to daughters Satyana, 4, and Keeva, 14 months.) "It'll be shorter. We'll get to the cake sooner! YAY renewal!!!"

PHOTOS: Celebrity weddings in 2013

Then, responding to a follower who suggested she have two cakes at the party, she tweeted: "Or 10 cuz that's the anniversary."

Married since October 2003, Hannigan and Denisof started out as friends after meeting on the set of Buffy in 1999. "Nobody could top my husband," she has said of the Angel star. "He was, like, beyond, beyond, super-dad, super-husband, super-man, definitely."

This article originally appeared on Alyson Hannigan, Alexis Denisof to Renew Wedding Vows: See Her New Ring!