12/04/2012 at 06:00 AM EST
Santa Claus is coming to town and Malin Akerman, Sarah Michelle Gellar, Tori Spelling
, Dean McDermott, Tiffani Thiessen and Ian Ziering were on hand to welcome him at the Second Annual Santa's Secret Workshop at the Andaz Hotel in West Hollywood.
Akerman was "eager to learn as much from the sponsors as possible about the best baby products on the market," an onlooker tells PEOPLE. "She even brought a notebook!"
Gellar brought her daughter Charlotte for some quality time, which they spent making crafts and posing for photos with Santa at the event, which was presented by Bill Horn and Scout Masterson.
Spelling and McDermott made their first public appearance with all four children – Liam, Stella, Hattie and newborn Finn – but it was more like a reunion for the cast of the original 90210
with Spelling, Thiessen and Ziering all in attendance.
"Tiffani's daughter Harper
saw Ian and ran over to him before sitting down to decorate a holiday photo frame at one of the craft tables," says another guest at the event, which benefitted L.A. Family Housing.
Ziering's daughter, Mia, also got hands-on at the crafts table. "Ian snapped tons of photos of his daughter. It was really cute. He's a super hands-on dad," says the guest.
– Melody Chiu, Marisa Laudadio & Aili Nahas