Mate in 11

 I rarely channel my "Inner Tal", but somehow this position spoke out for an attack...

White to play

I chose 19.Bxg7 and there followed Kxg7 20. Qc3+ and then Kf8

White to play : Mate-in-12 !

To be honest, after Qh8+, I think losing with White would be a difficult thing to do, although there is the scary part after the forced response of Ke7 when the White Queen is attacked by two Rooks. 

However, resolving that is probably the only hard part, and you would have to do that before playing Qa8 anyway.

Play continued with 21.Qh8+ Ke7, and with perfect/engine play there is now a mate in 11 to find.

Naturally, my play was not perfect, but Black's was even more flawed and I managed the mate-in-3 that I had visualised with 22. Nf6+ Kd8 23. Rxe8+ Qxe8 24. Qxe8#.

However, Black had given almost no resistance, unlike in the engine variation. 

Enjoy finding it !