"A lil bit of a peek!! Penny hurr," she captioned a black and white snap of herself.
Last week, the powerhouse singer explained that her part in the hit musical won’t be expanded to fit her star power and vocal ability.
"I don’t want to change anything about the role or how she develops," Grande, told reporters last Tuesday during the Television Critics Association press tour. "I just love Penny and it’s such a great honor to play her. I don’t want any special icing or parts."
"I never thought it would actually happen," she said of joining the live TV musical. "It's kind of surreal for me to even be a part of this. I'm so grateful."
Grande, who got her start on Broadway in the show 13, also recalled seeing the original Hairspray musical when she was younger, calling that cast "incredible."
"The fact that I’m here doing this today, sitting on this stage with such incredible people -- every time Harvey [Fierstein] speaks, like my heart bursts. A light goes off inside my heart. Kristin Chenoweth -- we're soulmates," she marveled. "I don’t even know what’s happening. My theater geek inside, which is what I am, I can’t take it. It’s very overwhelming and very exciting. Penny’s been my favorite character since the start."
"This is such a dream come true for me because at heart, theater is everything to me," Grande added. "Pop music is so fun, but this is way much more fun. So much more."
Hairspray Live! features a stellar ensemble cast, including Sean Hayes, Rosie O’Donnell, Derek Hough and Martin Short.