Only possible on the 1.0 version of the game.

You need to be Yoshi. Enter a Shifting Sand Land and choose a star where your cap can be stolen, now choose a cap to start with. Grab a box and have your cap taken away and boom. The end is to show that for whatever reason my DS fails to recognize the game after I crash it, I have to take the cart out and put it back in for it to work again