My family had enjoyed the Kitchen Sink Sundae at Beaches and Cream several times. We've even had it instead of lunch once or twice :-)
The sundae includes several flavors of ice cream, several flavors of sauce, bananas,
cherries, sprinkles, nuts, lots of
candy bars, brownies, cake pieces, probably a whole bunch of stuff I'm
forgetting, and an entire can of cream topping. You are more than welcome to ask for the sundae without nuts. Your server herself will make the Sink. It is custom made every time. You could also ask for the brownies and/or candy bars to be omitted from the sundae if you are afraid of contamination of these items. The restaurant staff will be happy to show you the labels from any item that is part of the sundae.
You should also know that there is
an entire department at Disney Dining dedicated to helping guests with
food allergies, food intolerances, other medical issues, and
religious-based food requirements. Just send an email describing
your situation to
SpecialDiets@DisneyWorld.com.
A cast member will get back to you with the information you need to
make sure that your family has a safe, and delicious, visit to WDW.
Another great resource for you is a book called PassPorter's Open Mouse for
WaltDisney World and the Disney Cruise Line. This sells for
approximately $20 and is available through amazon.com and many larger
bookstores. Open Mouse gives incredibly detailed information for Disney
guests with any sort of challenge, from anxiety to allergies and
everything in between.
Have a great trip!