"Pão de Queijo"

Literally, it means "Cheese Bread". Tough it was consumed very often in the Brazilian countryside, it was only in the late 40's/ early 50's that it became popular in the big cities. It is made of cassava powder - usually fermented, eggs, butter (sometimes vegetable oil or pork fat are used as to replace the butter), salt and obviously CHEESE! The most common choices are parmesan, mozzarella, and two chesses made in the province of Minas Gerais in Brazil; called "Minas Cheese" (white and soft) and "Regular Minas Cheese" (yellow and hard) the latter being a stronger tasting version of the former. 

Source:http://www.imagensporfavor.com/imagen/pao_de_queijo_-7699.htm

The "pão de queijo" is usually baked in the oven and, when properly made, it has a very crunchy crust and a soft and gummy core. Many people cut them in half and add some kind of jam (strawberry being my favourite - it tastes really great!!) or some creamy cheese. There is a fried version as well, known as "cheese biscuit". Tough it tastes pretty good, you can hardly eat lots of them: you will quiqly feel stuffed with them. 

 Source: http://desireemusic.blogspot.com/2009_08_01_archive.html

Usually, it is eaten with a hot coffe or a cold tea (usually the Brazilian "mate") at lunchtime, in the morning or afternoon. Nowadays it is an extremely popular snack in Brazil. The country exports frozen "cheese bread" to the U.S., Latin America and Japan, among others. The quality is surprisingly good, considering it is a frozen product..