Highest level

You get to play a bonus level up. You choose one out of three boxes for free. And you could get one, two or three donuts. If you are not happy with the choice, you can use your game cash to buy the opening of another box. It will cost you 50,000 dollars. If you are still not happy with the result, use another 50,000 to open the third box. Hence you could always get three donuts if you are willing to spend the money.

Note that the maximum donuts you can get is three. The donuts doesn't add up so you are not getting 6 donuts for opening all the boxes.