Hmm.. I have almost the exact same thing as you ( even the name of my base class is base!. Here is how I did it:
Parent Class ( contains logging method ):

package MARS::Base;
sub log{... }
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Child Class:

package MARS::Klarf1_2;
@UNIVERSAL::ISA = qw(MARS::Base);
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Main Script:

my $K = MARS::Klarf1_2->new();
   $K->log( 'Blahh blahh blahh' );
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This works fine for me...