Whisk together milk, flour, vanilla, salt, eggs and cinnamon in a large bowl. Run through a fine mesh sieve into another large bowl.  Cover and set aside for 10 minutes. Batter should be thin and runny, resembling pancake batter.

Place sugar in a large shallow plate and set aside.

Heat approximately 1-inch depth of oil in a frying pan over medium heat.  Dip rosette mold or buñuelera in oil, making sure mold is evenly covered by hot oil.  Working quickly, dip hot-oiled mold into batter, covering bottom of mold and sides, do not cover top of mold. Dip in hot oil, carefully shaking mold up and down until batter unsticks into hot oil.  Fry for 10 seconds or until browned lightly.  Turn using wooden skewer, fry for 10 seconds more.

Transfer buñuelo to a paper towel-lined plate to absorb excess oil.  Place in shallow plate with sugar and  cover lightly with sugar on both sides using a spoon. Place on a large tray and repeat until all batter has been used.