Black plays and wins in 5 moves https://lichess.org/HLPBzOnd/black
1... Bc5+ 2. Ka2 Nc4 3. Ka1 Kb3 4. Kb1 Na3+ 5. Ka1 Bd4#
The analysis board does a very similar checkmate in 5 moves
1...Ba5 2. Ka2 Bb4 3. Ka1 Nd3 4. Ka2 Nc1+ 5. Ka1 Bc3#
Source:
https://www.amazon.com/Chess-Puzzles-Advanced-Expert-Level/dp/B0917YQZP1