Fill a Dutch oven with 2 inches of vegetable oil and heat it to 365°F while you make the churro batter.
Vegetable oil
In a small saucepan set over medium heat, add in the water, butter, and granulated sugar. Bring the mixture to a boil and stir until the butter has melted and the sugar has dissolved.
½ cup water, 4 tablespoons unsalted butter, 2 tablespoons granulated sugar
Remove the pan from the heat and add the flour, vanilla, and cinnamon. Stir until fully combined.
½ cup all-purpose flour, 1 teaspoon pure vanilla extract, ¼ teaspoon ground cinnamon
Set the mixture aside to cool for 5 minutes.
Next, add the egg and mix to combine.
1 large egg
Transfer the mixture to a piping bag fitted with a star tip.
Very carefully, pipe the churros directly into the oil and use sharp scissors to cut the dough at about 3 inches.
Fry for 1-2 minutes, or until golden brown. Remove the churros to a paper towel to drain any excess grease. Repeat with the remaining churros
For the classic churro coating, combine the granulated sugar and ground cinnamon in a small bowl. Toss the warm churros in the cinnamon sugar and enjoy.
½ cup granulated sugar, 1 teaspoon ground cinnamon