Heat vegetable oil in a deep fryer or sauce pan to 375 degrees Fahrenheit (200 degrees Celsius). The oil should be 2 to 3 inches deep.

In a separate saucepan, combine water, salt, sugar, and melted butter.

Bring the mixture to a rolling boil.

Add the flour all at once to the boiling mixture.

Beat vigorously with a wooden spoon until the dough is smooth, thick, and pulls away from the sides of the pan.

Remove the saucepan from heat and let the dough cool slightly.

Add eggs one at a time, beating well after each addition, until the dough is smooth and shiny.

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

Carefully squeeze 6 to 7 inch ribbons of dough into the hot oil, slicing them off with a knife or scissors.

Cook 2 or 3 ribbons of dough at a time for about 5 minutes, or until golden brown and crispy.

Remove the churros from the oil using a slotted spoon.

Place the cooked churros on paper towels to drain excess oil.

While the churros are still warm, sprinkle them generously with granulated sugar, confectioner's sugar, or a cinnamon-sugar mixture.

Serve the churros immediately while they are hot and crispy.