Unapologetically original. Unabashedly in your face. Avril Lavigne's 2002 debut Let Go gave young women a defiant voice and set it to music they could rock out to. Fourteen million albums and eight Grammy nominations later, the Canadian chanteuse returns with Under My Skin but if you're expecting a whole lot of the same, you've got another thing coming. This is not a girl who rests on her laurels.

Under My Skin opens with the dramatic tracks "Take Me Away" and "Together," which set the scene for the kick-ass guitars and radio-ready chorus of "Don't Tell Me," a song of willful female empowerment that picks up where "Complicated" left off. From there it's a one-two punch of three-chord guitar licks ("He Wasn't") and head-bopping optimism ("Who Knows") alongside swirling, brooding melodies ("Freak Out") and moody tracks ("Forgotten," "Nobody's Home") that reveal a darker side of Avril Lavigne.

"I grew up so much in the past two years," admits the Napanee, Ontario, native. "I've been through a lot, I've learned a lot, and experienced a lot both good and bad. These songs are about all of that, and each is very personal to me." Working with producers, Butch Walker (of the Marvelous 3), Raine Maida (of Our Lady Peace), Don Gilmore (Linkin Park, Pearl Jam), Avril co-wrote the dozen introspective songs on Under My Skin in near secrecy. "I'd just come off my world tour and got back to Toronto and was writing right away," the 19-year-old says. "I had no idea what I was going to do. No one did. People wondered if I'd run out of things to write about, but it was the opposite."

After a lunch date with fellow Canadian singer-songwriter Chantal Kreviazuk turned into a major chick-bonding session, Avril and Chantal sat down to write. The chemistry was ineffable. "We got together one night and all of a sudden we had a song," she says. "No one knew what I was up to, not my management, not my label." The duo got together the next night and wrote another song. "We did that for two weeks and wrote 12 songs." Momentum took over and by summer Avril was moving into Chantal and her husband Raine Maida's Malibu house to record. "I was only off my tour for a couple of weeks, and I was ready to record," Avril recalls.

The California air provided a needed escape from Avril's frantic life. "It was a great time for me, living out there, being out of the public eye, and having my independence. And my friendship with Chantal evolved into one of the best I've ever had." Chantal and Avril would spend all night in the studio perfecting the songs. During the day, Avril learned the city by driving to and from the studio and wherever she needed to be. No photos, no interviews, no pressure. Eventually they recorded most of the songs in Raine's studio, and those songs appear unaltered on Under My Skin. The rest of the tracks, co-written with her guitarist Evan Taubenfeld (and one track with former Evanescence guitarist Ben Moody), were cut just up the road. "I was involved in every aspect of making this record. I'm very hands-on," she says. "I knew how I wanted the drums, the guitar tones, and the structures to be. I understand the whole process so much better this time because I've been through it. I'm really picky with my sound."

Picking favorites out of her 12 hand-made babies is another matter. "They all mean so much to me, but I love ‘Together,’ which is all about being in a relationship and knowing it's not right. It's a song that basically says, it's not working out honey." A couple of other tracks mine dysfunctional relationships and have hooks as catchy as those on "Complicated" and real-life narratives (like "Sk8er Boi"), but what truly underscores Avril's growth are the more positive tracks, such as "Who Knows" and "Take Me Away." "I guess that's just the way that I am now," admits the former supposed attitude junkie. Deep, piano-driven tracks like "Together" and "Forgotten" reflect Avril's growth, maturity, and change since the release of Let Go. "I'm happy with what I'm doing and have faith that everything is going to work out for the best." She's also found a feminine side to offset her well-publicized tomboyishness. "I'm such a chick. I'm a hopeless romantic, and surprisingly old-fashioned," Avril laughs. "That's why I wrote a song about not giving it up to just any guy ["Don't Tell Me"]." Girly quirks aside, Avril's anxious to get the show on the road. "It feels so good to be singing new songs," she says. "I feel refreshed and I'm looking forward to the next thing."

Optimistic or melancholic, Avril's two-year wild-ride on the rock-star express has shaped her world view and taught her a whole lot about balance. "The songs on Under My Skin are definitely deeper than those on Let Go," she says, "But I still love a good pop song. I'm basically just a girl who likes to write, who likes to rock out, and who wants music to be a part of my life forever."

She's also just a girl with a bell-clear voice and the ability to bottle youthful anguish and enthusiasm into tidy, infectious songs. Avril Lavigne's Under My Skin is sure to get under yours.