Pao de queijo had been introduced to the Brazilian culture back in the XVII century.     However, by this time, cheese wasn’t part of the recipe.

Everything started when the slaves of Minas Gerais were making Manioc Flour to rich farmland owners. That was pretty much the time when feijoada was invented as well.

Going back to pao de queijo history , the slaves used to crop manioc ( yucca root) peel them off  finely grate them , and soak them with in a big wood bowl (gamela) with plenty of water . So they washed and drained this grated manioc, spreading it on a tiled floor outdoors and let it dry under the sun.  

When dried they scraped this manioc into big bags and stored them for food consumption trough out the year.  This was a noble food prepared to the rich farmland owners. Therefore slaves were not supposed to eat them. From the leftovers ( dried manioc starch ), they made smalls balls and baked them. This became a very popular food among the slave population and discarded by the rich ones.

More then 200 years later, cattle farms became widespread in Brazil. Slaves ( that were being freed by that time) gained access to all sorts of dairy products, incrementing the baked balls with milk and ultimately with CHEESE.

When Brazil had no more slaves, their culture started to spread among the rest of the population. Pao de queijo became a very popular food in Minas Gerais and throughout the country.