Fill up gap between door frame and surface of plasterboard

[Alexx]

One of the sides of my wall is around 10mm off level to my door frame as I built up 3 layers of plasterboard with tecsound in between to lower the noise transfer, as this is a home office. I was thinking about how to fill this gap with a strip of wood, but I need to plain it at an angle and I've no idea how I can best achieve this. maybe there is a DYI friendly tool to assist with that? I was thinking even about using a wood filler, but I guess it would be too much at the top where the difference is 10mm, but maybe at the bottom where there is little difference it would work? I hope the pictures help getting a better idea? Thanks!

 

https://imgur.com/a/SP29XIm

Edited August 13, 2022 by Alexx

[Mr Punter]

Could you use a corner moulding on this side instead of architrave?

[Conor]

We had this. Joiner ripped sheets of MDF to make full depth door stops that finished flush. Then architrave.

[Iceverge]

+1 for ripped MDF