"We do have a special performer we're very excited about, but they're actually not a boy-bander. It has to do with another musical passion I've had in my life," Ashley told Entertainment Tonight while attending iHeartRadio's 102.7 KIIS-FM Wango Tango concert on June 1.
"It's David Cook from American Idol. Yeah, he is one of my favorite artists ever -- I mean my favorite American Idol ever! So it is really cool that he is going to perform at our wedding! He has the warmest voice ever. He can just warm up an entire room, so we love that romanticism."
"Yeah, we [were] kind of joking one day about, 'What if David Cook sang at our wedding? And then we were like, man, now we have to do it,'" Jared added.
"So we were able to talk to the right people, and he wanted to do it, and it all worked out."
Ashley and Jared then wasted little time setting a wedding date, and announced they planned to get married in August 2019 only a couple of months later.
The couple also announced they planned to have their friend and fellow former Bachelor in Paradise participant, Tanner Tolbert, serve as the officiant at their wedding ceremony, which will be in Newport, RI.
"Tanner has a plan, if the baby is born a week early then he's going to make it. If it's within the week, it will be a little more challenging, but it's going to all play it by ear. Our backup officiant will have definitely a role in the wedding either way."
Ashley and Jared also clarified that former The Bachelor star Nick Viall -- another close friend that is part of the wedding party and publicly offered to officiate the ceremony last year -- is not the stand-by officiant.
"No, it's not Nick... Nick's a part of the groomsman party," Jared said.
"He has a job at the wedding as well," Ashley added.
According to the couple, The Bachelor host Chris Harrison is also not the backup option.
"No, it's not Chris," Ashley said.
"We really hope Chris comes though. We figured we'd give him a wedding off -- just enjoy, sit down, eat the food, dance. Enjoy yourself, no work for Chris!" Jared added.
"We are going to be really sad if Chris doesn't go, so Chris you better!" Ashley joked.
Ashley and Jared's wedding reception venue can only will feature a maximum of 180 guests -- which has caused some hurt feelings and public drama from those left off the guest list.