In a medium saucepan, combine the water, unsalted butter, granulated sugar, cinnamon, and salt. Bring to a boil over medium heat, stirring occasionally to melt the butter. Remove from heat and stir in the flour until a smooth dough forms that pulls away from the pan sides.
Transfer the dough to a mixing bowl and let cool for about 5 minutes. Add eggs one at a time, beating well after each addition until dough is smooth and glossy.
Heat oil in a deep frying pan or pot to 350°F (175°C). Test by dropping a small piece of dough; it should sizzle and float quickly.
Using two teaspoons or a piping bag with a small round tip, drop small dollops of dough into hot oil. Fry 2-3 minutes, turning occasionally, until golden brown and crisp.
Remove churro bites with a slotted spoon and drain on paper towels. While warm, toss in a bowl with cinnamon sugar coating (1/2 cup sugar mixed with 1 teaspoon cinnamon) until evenly coated.
Serve warm, optionally with dipping sauces like chocolate or caramel.