Yep looks like, Bakumatsu Shishi Channel's local meme. Origin is hard to track since video where this phrase first appears is behind a paywall (should be https://www.nicovideo.jp/watch/1446466319 around 15:27). Best description I could find is 坂本がたまに発する喜悦の言葉, Sakamoto's (one of channel coauthors) occasionally used word of joy. やったでおい used mostly in context of some kind of accomplishment in game, as far as I understand.
Huh. Roon wants headpats instead of hugs? That’s new.
Hopefully she doesn’t come home with blood in her hair.
Can do!Commander, hug!Okay!I would have said that, but I'm sure you would rather give headpats than hugs.Hmm, true that, I want to pet.Then it's fine to pet me~From now on, let me have some headpats instead of hugs, every day~Let's do that~