Mutually Supporting Pawns
I thought it was really cool to actually apply the mutually supporting pawns idea. It's always a good feeling to use some endgame technique from the books; you get direct proof that your study was worth it.
Paradoxically, White's 2 split pawns defeat Black's 3 conjoined trio.
White to play:
2.Ke2 c3 (say)
3.Kd3 ... Now Black's pawns advance to their doom, whereat the lone Blck K finds itself in "Zugzwang".
And now we see why the BK dared not move previously: