In a Blender, combine the milk, egg, oil, Parmesan cheese and salt until combined. You should add the liquids first, and the tapioca last, otherwise the tapioca will gum up to the blades and be impossible to mix.
Once combined, add the Tapioca Starch/Flour 1/2 cup at a time until all of the tapioca flour has been added.
Add mussarela (or any other preferred cheese) and mix with a spatula. Tip: You can also add more or less cheese, it’s pretty flexible. It’s important to use one cheese that has a stronger flavour like Parmesan because it’s really the only flavour you’re putting in there and another mild one. I like a mixture of Parmesan and mussarela. But play around with it and find your perfect mix. You can also use, for example, Friulano or Pecorino Romano or Monterrey Jack or Swiss, and even Gruyere or cheddar. All great!
Preheat oven to 375-400°F (190-200°C.).
Grease around the insides of each mini-muffin pan (Tin or Silicone) thoroughly with Cooking Spray.
The batter will be very liquid, pour the batter into your greased mini muffin pan just until half full because it will double the side when cooking. It’s a very thin batter so pour slowly!
Optional: sprinkle a little more Parmesan cheese on top.
Bake until barely golden brown and puffed, About 15-20 minutes. Remove from the oven and transfer to a Serving Bowl.
Serve warm. They are at their crispiest best when they're still warm from the oven. Unless they are eaten warm, they will soften, so I recommend making and eating fresh. But they usually won’t last too long once they come out of the oven.
Batter can be made ahead of time and kept in the fridge for up to one week.You can also try adding a variety of herb seasonings, such as Italian seasoning or oregano.Don’t be concerned if the rolls sink in the middle. It’s perfectly normal for them to sink down in the centers and they taste exactly the same!Pão de queijo is a typical Brazilian snack, originally from the states Minas Gerais and Goiás, they are usually eaten with “cafezinho”, a tiny cup of coffee (like expresso coffee), or with wine or beer, in most of all birthday parties and as appetizers preceding dinners. They are also served with with a glass of ice cold Guarana (Brazilian soda)!Feel free to serve them with cream cheese, Requeijão (Brazilian Cream Cheese), butter or even some dulce de leche! Yum!Tapioca flour or Tapioca starch is extremely common flour for gluten-free cooking and one that I’ve used in many other recipes. For that matter, tapioca flour is sometimes considered to be the best performing gluten-free flour out there. It’s really smooth, soft flour that feels much like cornstarch. It’s made from the ground roots of the cassava (also called yuca) plant and it’s gluten free for those of you that care about that. It is actually a type of starch, rather than what we would typically consider to be "flour". As a starch, tapioca flour tends to be extremely low in nutrients. But, it is also low in calories and has no sugar or gluten, which are all key advantages. In terms of flavour, tapioca tends to be mild, with a slightly sweet taste. This makes it a good complement to many different types of food and is another reason why you find tapioca flour used over and over again in recipes. The low calorie count also makes this an especially good flour for people who are trying to lose weight or simply decrease their calorie intake.Tapioca Starch/Flour, and it’s actually easier to find than you might think. It’s really smooth, soft flour that feels much like cornstarch. It’s made from the ground roots of the cassava (also called yuca) plant and it’s gluten free for those of you that care about that. You can find Tapioca Starch/Flour on Amazon, for a relatively good price – or, check the gluten free isle of your well stocked local grocer. You can also find tapioca flour at Asian and Latin American markets as it’s used in a lot of their cooking, and also at health food stores and places like Whole Foods where you can find a good selection of wheat flour alternatives.The only substitute you can use are: Sour Manioc Starch - Polvilho Azedo or Polvilho Doce as they are pretty much the same. You can NOT substitute any other type of flour, I would NOT recommend using Rice, Coconut or Almond Flour as that will change the texture completely. The tapioca flour is key, so when you find a good place to buy it, stock up!If you don’t have a mini muffin pan, feel free to use a larger muffin pan – your final count will be significantly less.You can also buy pre-packaged Cheese Bread Mix (Mistura para Pão de Queijo), they are delicious but they’re not quite the same as this homemade ones.