blessing - Washing hands for eating pizza

How many slices are required to make you responsible to wash on Pizza?

Answer

1. 
   

   The opinion of Harav Moshe Feinstein zt”l holds two slices makes you responsible to wash.(I believe this would be the Main Psak (Halachic Ruling) for American's)

   
   


2. 
   

   Harav Shlomo Zalman Aurbach zt”l, and Harav Elyashiv say any Pizza would require one to wash and bentch (V'zos Habrocha page 230).

   
   



3. 
   

   Rav Belsky Shlita Rosh Yeshiva of Torah Voddas and Posek for the Orthodox Union says
   two slices would only be a meal if they are eaten with something else, such as a knish. While I personally ascribe to 3 each person should seek Rabbinical counsel for this and all other question.

   
   

Square otherwise known as Sicilian pizza which is made by first baking the dough and then adding the cheese is always Hamotzei the same applies to Pita-Pizza made by taking a Pita and putting cheese and Ketchup on it the Bracha also maintains it's Hamotzie status.

The above is a summary of a recent Halachicly Speaking article available here: http://www.ladaat.net/siteimages/fl_4c1258431c6eb.pdf