SharePoint PnP Author column with PowerShell

Hello all,

I have done a lot of reading and can't seem to find the answer. I am working on my first PnP script to pull all the data from a SharePoint site and save it into an CSV file. So far everything is working but one thing.

I can not get the "Author" column to save correctly. I assume it is because this data is a "Table" technically, instead of a record, but I am not sure how to specify what I want to return.

Here is a demo code I am working with.

Connect-PnPOnline -Url "MYSITE -UseWebLogin

(Get-PnPListItem -List "MYLIST" -Id 521 -Fields "Author").FieldValues

This returns

Key Value

--- -----

Author Microsoft.SharePoint.Client.FieldUserValue

Any idea how I get it to return the .Email of the user?

EDIT: So I found that if I use 

$listItem["Author"].LookupValue 

I can get the lookup value of the column, however, I can not figure out how to get this into my Hashtable. 

$obj=New-Object PSObject
$listItem.GetEnumerator() | Where-Object { $_.Key -in $Global:selectProperties }| ForEach-Object{ $obj | Add-Member Noteproperty $_.Key $_.Value }
$hashTable+=$obj;
$obj=$null;