MIAMI -- When we first met Aaron Carter, he was a pre-pubescent, mop-topped singer best known for being Backstreet Boy Nick's little brother. Now, as the blond heartthrob nears adulthood, Carter is looking to ditch his teenybopper persona and churn out, well, grown-up music.

"I'm taking my time trying to transition because the Aaron Carter you saw back then -- now [I'm] a completely different person," the 17-year-old singer told MTV News. "My voice has changed. It's gotten more mature. It's going to be more adult oriented and not just for little kids."

The pop crooner was only 10 when he found international fame with his 1998 self-titled LP. U.S. success came with 2000's Aaron's Party (Come Get It), which went double-platinum in the U.S. and hit #4 on Billboard's albums chart thanks to the in-your-dreams single "That's How I Beat Shaq."

Now, Carter is looking to recruit one of the industry's most sought-after beat makers to produce a follow-up to 2002's Another Earthquake, which failed to make a blip on the charts.

"I'm actually going to be working with Pharrell Williams probably at the end of the year, when I turn 18," the singer said. "When that big day comes, we're gonna lay down some hot tracks."

Carter is also intent on having more creative input this time around. "I'm starting to write all my own music and own my own style," he explained.

But before he hits the recording studio, the singer/actor -- who can currently be seen onscreen in the motorcycle-racing action flick "Supercross" starring Mike Vogel ("Sisterhood of the Traveling Pants") and Sophia Bush ("One Tree Hill") -- will be in Los Angeles for the next two months making his rounds in the über-competitive audition circuit, looking for his next big-screen gig.

In the meantime, Carter has the teen romance "Popstar" ready for release. The singer plays -- you guessed it -- a famous pop star in the film. Riding high on his fame, Carter's character is slapped back to reality by his mother, who forces him to go back to high school to raise his failing home-school grades. If the teenage superstar doesn't pass his classes, his sold-out summer tour gets scrapped.

"It's a love story," Carter explained. "I [get this girl to tutor me] and end up falling in love with her."

Brace yourself for some '70s throwbacks -- former teen idols David Cassidy and Leif Garrett make appearances in the film, set for DVD release in November.