A first attempt...
At first blush, it might make sense to try and simply write the list variable directly to the spreadsheet, using an approach something like this:
However, using this approach, your entire list will be written to a single cell of the spreadsheet.
Instead, use a Loop!
Place your Excel or Google Sheets module inside a Loop module. Instead of adding the List variable directly to your spreadsheet, add the List Item variable created by the loop module.
Now, each item in your list will be written to a different cell in a single column!