The 23-year-old joined the Soweto giants from Richards Bay at the start of the season, having finished as their top scorer and attracting interest from several Betway Premiership rivals.
Mbuthuma came off the bench to score twice in Pirates’ 4-0 CAF Champions League victory over Lesotho side Lioli.
Ouaddou praised the youngster’s impact, describing him as a player for the future.
"Mbuthuma is one of the most talented players in South Africa. Our scouting department at the club did a great job of bringing him in, and now we are trying to turn him into a top top striker."
Another player that impressed the coach was midfielder Sipho Mbule, whose versatility Ouaddou sees as a huge plus for the team.
"What I like to see is Mbule smiling when he is playing. He is a fantastic player and one of the best players in this league. So when he is happy, I'm happy."
Meanwhile, Pirates have strung together eight straight wins, and Ouaddou was asked whether he had made any key adjustments since facing heavy criticism earlier this month.
"I did not change anything. I trust in the work that I am doing, and the love that I'm giving to my job, and my team."