These cheesy rolls originally come from Brazil. They’re crunchy on the outside, and soft and chewy inside.
Adjust oven rack to middle position and heat oven to 375 degrees. Spray 12-cup muffin tin with vegetable oil spray (making sure to get inside each cup).
Add milk, cheddar cheese, Pecorino cheese, oil, eggs, and salt to blender. Add tapioca starch. (Make sure to add the tapioca starch last, or the mixture will turn to glue in the blender.) Place lid on top of blender and hold lid firmly in place with folded dish towel. Process on high speed for 30 seconds. Stop blender.
Use rubber spatula to scrape down sides of blender jar. Replace lid and process on high speed until smooth, about 30 seconds. Pour batter evenly into greased muffin tin cups, filling each cup about three-quarters full.