You can either push to the inner array, or you can assign to its particular member: 
#!/usr/bin/perl
use warnings;
use strict;

use Data::Dumper;

my @AoH = ({key1 => 'value1',
            key2 => 'value2',
            key3 => [ { var1 => 'val1',
                        var2 => 'val2',
                      },
                      #NEED TO ADD ANOTHER HASH HERE
                    ],
           },
          );

push @{ $AoH[0]{key3} }, { key => 'value' };
#    ^       ^   ^
#    |       |   |
#  deref    0th  |
#  as an    hash |
#  array         key in
#                the hash

$AoH[0]{key3}[2]{another} = 'way'; # if you know the index.

print Dumper \@AoH;

[download]
($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

[download]

In reply to Re: Problem with nested array/hashes by choroba
in thread Problem with nested array/hashes by Dandello

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