In a saucepan, combine water, butter, and sugar. Bring to a boil over medium heat.

Remove from heat and stir in flour until mixture forms a ball.

Allow to cool slightly, then mix in egg and vanilla until smooth.

Heat vegetable oil in a deep fryer to 375°F (190°C).

Transfer dough to a pastry bag fitted with a star tip.

Pipe small bites into hot oil, frying until golden brown, about 2-3 minutes.

Remove with a slotted spoon and drain on paper towels.

In a bowl, mix sugar and cinnamon. Toss warm churro bites in the mixture until coated.