You should be using value, as per the documentation. value returns a hash when the a hash was used to create the cookie.

%user_data = $cookies{'user'}->value;
print($user_data{field1}, "\n");
print($user_data{field2}, "\n");
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assuming you used the following to create it:

$user_cookie = new CGI::Cookie(
   -name => 'user',
   -value=> {
      field1 => 'value1',
      field2 => 'value2',
   }
)
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By the way, the cookie will look something like:

user=field1&value1&field2&value2; path=/
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