Hardest mate in 1 puzzles

Is this possible?

I know there is a mate in 9

Yes.

4.6 The act of promotion may be performed in various ways:

4.6.1 the pawn does not have to be placed on the square of arrival,

4.6.2 removing the pawn and putting the new piece on the square of promotion may occur in any order.

4.6.3 If an opponent’s piece stands on the square of promotion, it must be captured.

In 4.6.1 "does not have to" is distinct from "may not be". In fact 4.6.3 suggests that in the case of a capture the pawn must be moved to its 8th. rank because that is the only way to capture according to art. 3.

Although it's a legitimate board layout in a chess game it's possibly only a legitimate board layout in an illegal position according to 

3.10.3 A position is illegal when it cannot have been reached by any series of legal moves.

because White has not yet made his move according to

 4.7 When, as a legal move or part of a legal move, a piece has been released on a square, it cannot be moved to another square on this move. The move is considered to have been made in the case of:
...
4.7.3
promotion, when the player's hand has released the new piece on the square of promotion and the pawn has been removed from the board.

But that's questionable because he has made his move according to 

4.7.1 a capture, when the captured piece has been removed from the chessboard and the player, having placed his own piece on its new square, has released this capturing piece from his hand,

That could lead to arguments if competition rules are in force and White presses his clock at that point. How should the arbiter interpret 7.5.3?

7.5.3 If the player presses the clock without making a move, it shall be considered and penalized as if an illegal move.

Unfortunately there's a lot of stuff like that in the FIDE laws.

There's a reason why this option exists..

As you can see, it is set to on for me, showing legal moves with the help of dots that the selected piece can legally move to, however...

It doesn't show a dot on the en passant square on f6, meaning that en passant is illegal in this position.

So I do not see how you solution is a legal move...

@MARattigan Yes. I DO agree with you.

If the pawn had promoted into a queen or rook, it's checkmate to Black.

However, if it promotes into a bishop or knight, it's a draw.

P.S: That WAS my puzzle, so I did it for a puzzle.

The fact that you have only one dot is because you didn't specify a possible e.p. capture square when you set up the position.

Puzzle conventions are that you take into account only what is visible and an e.p. capture is possible only if it can be proved to be possible.

In this case it can't. Either case is legal.

Nxc4#?

this is literally checkmate just sitting there its already solved

do you like it? (this is my first time making a puzzle! (white to move)

Don't checkmate in 1 move

Might be better with the right side to move.