This endgame can come out of the scotch gamibt, albeit there are better lines for a black player that desires a draw. However, I was wondering out of curiosity if this is good for white or black.
Komodo 9.3 evaluates the position after 1.Kd5 (after searching to 31 ply) as +2.32 for White. Playing out a few lines, White usually ended up with Q+2P vs Q+P. It's not necessarily winning (Q+P endings have lots of resources for the defender due to all the checks) but I am comfortable asserting that the position is more pleasant for White.
For what it's worth, the position has occurred 6 times in my database, with 4 White wins and 2 draws.
Stockfish 9 at d= 44(in a demo) give more than 9 points as White, maybe the setting was for a corrispondence game.It appears that starting from 2012 six piece ending are considered wins if they lead to mate, even if the 50 move rule has to be broken in the process. Starting from January 1, 2020 it is also true for 7 piece ending. Corrispondence chess.
Now I just did a deep analysis with Stockfish 14.1 NNUE depth =73 three quarters of an hour, and it is winning right away , with or without the 50 move rule. The position is evaluated at +5.02 for White , and , most importantly , the line reaches a winning seven pieces ending according to Syzygy tablebases online. The riddle is now solved : the Scotch Gambit ending is a win for White.
I got very deep and reaches the conclusion that the ending is a draw in over the board chess ( but it is nearly impossibile to defend) but a win in correspondence chess. The key position with WHITE King in c6 Queen in c1 pawn in b7 BLACK King in h2 Queen in b3 pawn in g5 Black to move, that is indeed a mate for White, but 58 moves are needed before a pawn move or a capture. Syzygy tablebases online. Only six pieces are present at the board at this point.