Create a "vhost.conf" file in "/var/www/vhosts/<DOMAIN.TLD>/conf/"
<Directory /var/www/vhosts/<DOMAIN.TLD>/httpdocs>
php_admin_value safe_mode off
php_admin_value open_basedir none
</Directory>
Rebuild the domain configs for the particular host via:
/usr/local/psa/admin/sbin/websrvmng -u --vhost-name=<DOMAIN.TLD>
or rebuild all via:
# /usr/local/psa/admin/sbin/websrvmng -a