So here it is: the BBK
All your nice words about my last experiment gave me the drive to get it done, thank you all for that!
I knew I had a "butterfly comb" laying around somewhere.
I cut off the comb part of it with an angle grinder and then cut the knife blade to the right size.
I did not remove the handles though and that ended up biting me in the ass...
Using a magnet, I positioned the blade against and in line with the stub left from the comb and proceeded to stick weld them together.
I was dreading that moment as I'm not good with welding and even worse when it comes to thin-ish material, but it went pretty smoothly and I'm happy how it turned out!
I then went on to grinding. I tried removing the handles but only one came off, the heat from the welding must have something to do with that...

Anyways, the hard part was behind me and all that was left was to grind, sand and polish it as well as my impatient self was willing to.
And there it was:

In all its splendor

The

Butter

Fly

Butter

Knife
Spreading butter properly with pizzazz