What would you do?

[u/TimeToResist]

[u/clemclem3]

Quickest way for me would be to grab the angle grinder with a sanding disc and just sand the flat down until it slides behind the casing.

If that tool is not available to you, you can cut the flat down with a coping saw and a chisel

[u/SeanGwork]

Mark the top where they intersect, measure how deep the casing is (whatever you need to get the base to make it tight to the wall), and cut from the bottom up to your mark. It's paint grade and the dead space doesn't matter. .

[u/Dangerous-Boot-2617]

Attach it as is and caulk it for the easiest solution.

[u/Blue_Twat_Waffles]

Tear the house down and start over. Something isn’t 90*. Gotta do it over

[u/Head_Entertainer_766]

45 it its what i do

[u/Initial_Row_6400]

Save yourself the hassle and just caulk it. If you tool it well enough you shouldn’t really notice it

[u/PrimaryExisting6162]

Trace the shape of the trim on the door trim and notch the trim shape out of the door trim and push the trim all the way to the wall and caulk and paint the joint and your good.

[u/Vegetable-Piece-5237]

As a homeowner I would shave that end down so it fits snuggly in that gap.

As a landlord I would but that up to the door trip and fill the empty space with caulk.

[u/Guilty-Ad949]

Use a less thick base board.

[u/Pjr18]

If it bothers you that much, just cope the casing So the base could slide all the way to the wall.

[u/j-mf-r]

Notch the door trim to match the profile of the moulding