There have been several attempts at putting two engines into a Mini. They are often called a Twini-Mini.
The most famous Twini-Mini was the one that John Cooper built, which reputedly was almost the death of him.
Jay Leno has a 2002 twini mini in his garage.
I have no idea where this one came from, but it does get brought out to shows quite a lot, and is (obviously) very cool!