01 - Combine granulated sugar with ground cinnamon in a shallow bowl and set aside.
02 - In a medium saucepan, bring water, butter, sugar, and salt to a boil over medium heat. Reduce heat to low, add flour all at once, and stir vigorously until mixture forms a smooth ball and pulls away from the sides.
03 - Remove pan from heat and let dough cool for 5 minutes. Spoon the dough into a pastry bag fitted with a large star tip.
04 - Heat about 2 inches of vegetable oil in a large heavy-bottomed pot to 375°F (190°C). Pipe 2.5 cm (1-inch) segments of dough directly into the hot oil, cutting with scissors. Fry in batches, turning with a slotted spoon until golden brown, about 2–3 minutes per batch.
05 - Transfer fried bites to a paper towel-lined plate to drain briefly, then roll immediately in the cinnamon-sugar mixture while still warm.
06 - Arrange the coated churro bites on a serving platter and enjoy warm.