Cache::Cascade distributes "both", a .pm file and a .pmc file. And the file Cache/Cascade.pm contains the line

use tt ( methods => [qw/size count/] );
[download]

So I suggest you contact nothingmuch about building his module. It seems that the .pmc is the macro-expanded version of Cache::Cascade, as generated by Module::Compile, but it further seems to me that his installation process does not install .pmc files properly.