With the spooled file extractor you can create transformations (with the extension .sfe), that can convert a spooled file into XML.
These transformations can be linked directly in a template, so that the spooled file is converted directly into XML, when you merge with the template.
Alternatively can you also convert a spooled file into XML with this basic, converter workflow component: SPLF to XML.
The SPLF to XML component has this parameter:
The parameter must be the path to an .sfe file in the transformations.
The input payload is a spooled file (SPLF) and the output payload is XML.