In a medium saucepan, combine the water, butter, sugar and salt. Bring to a boil over medium heat. Remove from heat.
Add flour in butter mixture. Stir briskly until a ball forms. Put dough into a mixing bowl and let cool for 5 minutes.
Whisk the eggs and vanilla extract in a small bowl.
WIth an electric hand mixer on medium speed, beat half of the egg mixture until just combined. Mix in the remaining egg mixture until completely smooth.
In your frying pan or electric fryer, heat the oil to 350°.
Set up a piping bag with a star tip and fill it with half of the dough.
Squeeze 3-4 inch lengths of dough into the hot oil. Use your non dominant hand to squeeze and your dominant hand to cut the lengths off with scissors or a knife.
Fry churros 4 at a time for 2-3 minutes on each side. Turn with a slotted spoon.
When golden brown, remove to a paper-lined plate to drain.
While still warm, gently coat with sugar cinnamon mixture and set aside.