Rotate Character Slowly Towards Mouse Position?

I’m making a little top down shooter game, where a ship faces the mouse position. Problem is, I don’t want it to rotate instantly, I want it to rotate over time. I tried putting interpolation nodes everywhere I could think within what I have and it doesn’t seem to take…

I’ve also been all over YouTube and the forums, I can’t find a way to do this. I’ve been at it for days now, I could really use some help. Anything to just point me in the right direction.

I realize it’s probably a pretty simple problem but here’s what I have so far, thanks for any help in advance.