Crash the game and bring up the exception handler. (For anyone that doesn’t know, the exception handler can only be shown after pressing 1, 2, 1, 2, -, +, -, +, then A after causing a massive glitch. Time starts upon first movement of Mario (to 1-1,) time ends when the handler appears on screen. There are two ways to do this, you can either A - eat 4 berries, then eat the 5th one with Yoshi and get damaged on the exact same frame, or B - use the infinite coin glitch in 4-C (I’m might be wrong about that) multiple times to overwhelm the game. One is faster, but the other one is MUCH easier. I would be interested to see how speedrunners would tackle this.
Thanks!
Here's proof that I'm not just making this up:
And it turns out that you have to press HOME, -, +, -, +, 1, 2, 1, 2, A. I have completed two runs with a PB of 3:11. (It's unrecorded, unfortunately, but I can attempt to get a recorded one.)