PowerShell copy an array completely

You can use serialisation to deep clone your array:

#Original data
$FruitsOriginal = Get-Fruits

# Serialize and Deserialize data using BinaryFormatter
$ms = New-Object System.IO.MemoryStream
$bf = New-Object System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
$bf.Serialize($ms, $FruitsOriginal)
$ms.Position = 0

#Deep copied data
$FruitsNew = $bf.Deserialize($ms)
$ms.Close()

# Copy the array here
$FruitsCopy = @()
$FruitsCopy = $FruitsCopy + $FruitsOriginal