Chris Lamb (aka lamby) has created two Debian packages for CakePHP which are now in the unstable distribution of Debian: cakephp with the core files, and cakephp-scripts, which contains bake.php and acl.php. The installation is very simple:
apt-get install cakephp
apt-get install cakephp-scripts
A drawback of using those packages is that they currently use the previous stable version of CakePHP (220.127.116.1150) instead of the current stable version (18.104.22.16897). But I think it will get updated soon.