In a saucepan over medium heat, combine water, butter, sugar, and salt. Bring to a boil.
Reduce heat to low and stir in flour. Stir continuously until the mixture forms a ball.
Remove from heat and let cool for a few minutes. Then add eggs one at a time, mixing well after each addition.
Stir in vanilla extract until smooth.
Heat oil in a deep pan to 375°F (190°C).
Transfer dough to a piping bag fitted with a star tip.
Pipe small portions of dough into the hot oil, cutting with scissors.
Fry until golden brown, then transfer to a paper towel-lined plate.
In a bowl, mix sugar and cinnamon. Roll warm churro bites in the cinnamon-sugar mixture.
Serve immediately and enjoy!