You are using package variables (what other languages call static) and in your update you have the right syntax. If you had an object, the way to access its parent's package variable is stated in perlobj, at the place you quoted it: for a static method: $self->SUPER::save(); and for a package variable %{$self->SUPER::cfg};

But package variables are not "object variables" or member variables (?whatever?). It would be better to store %cfg into $self's hash for at least one reason: inheritance is taken care by Perl for free. Whereas in your case, Perl takes care of the inheritance of Class1 into Class2 and YOU MUST (not forget to) take care of the inheritance of Class1's package variables. That's a lot of boiler work (for me ;) ).

related: https://stackoverflow.com/questions/3109672/how-to-make-a-hash-available-in-another-module and Perl Inheritance & module variables . The latter in particular is similar to what you have shown.