The 36-year-old singer took to Twitter on Tuesday to detail a special delivery she received courtesy of Underwood's activewear and accessories line, CALIA.
"Thank you @carrieunderwood," Clarkson captioned a clip featuring a gift celebrating the line's third anniversary. "This apparel cake idea was adorable! I’m just now receiving it because it’s been at Starstruck! Love all your gear girl! #Calia #FannyPackForTheWin"
In the video, the beloved Voice coach can be seen excitedly opening a five-tier "cake" comprised of colorful gift boxes.
"Carrie Underwood, this is adorable," Clarkson gushed. "I don't know if you came up with this, but your company is turning three, congratulations!"
The American Idol winner continued, saying she loves everything she has received from the apparel line.
"I love all your stuff you always send me," she added. "It's a cake. It's in the shape of a cake because they're turning 3, y'all. Who came up with this? That's adorable. Each one is a drawer with a gift."
The mother of two also revealed some other good news, saying she's "lost weight" in recent weeks.
"And Carrie Underwood, thank you as well because I've lost weight since you sent this," Clarkson admitted, just before cheering. "So it's all too big for me which made me feel really thin. But I'm gonna find someone that loves it."
While CALIA is well known for its workout tanks and leggings, Clarkson confessed that it's the brand's socks she most prefers.
"I love your socks best. I know that's funny, but your socks and your fanny pack are my jam," she said. "But I love it! This is amazing. Whoever thought of this cake idea, this is great. Good job, Carrie Underwood and team."
The "Piece by Piece" singer has looked noticeably slimmer as of late, and she recently revealed her "secret" to ET's Sophie Schillaci, jokingly chalking it up to a fashion-induced illusion.
"I have to shout out my whole glam squad," Clarkson said, before laughing, "I literally hired Harry Potter and SPANX, it's all like a sausage."
All joking aside, the GRAMMY winner is looking great. See below for more on the stylish star: