Ashlee Simpson has announced some very important dates! Her new single, "Little Miss Obsessive," which features Tom Higgenson of Plain White T's, will be digitally released on March 11. Then, her full-length album, "Bittersweet World," hits stores and will be available digitally on April 22.

Ashlee collaborated with some major players on this album including Timbaland, The Neptunes' Chad Hugo, and Kenna. She felt "very lucky to work with people who are at the top of their game."

"Little Miss Obsessive" Audio Streams:
Windows Hi | Windows Lo