In a small saucepan over medium heat, combine water, 2-1/2tablespoons sugar, salt and 2 tablespoons vegetable oil. Bring to a boil and remove from heat. Stir in flour until mixture forms a ball.
Heat oil for frying in a deep fryer or deep pot to 375°F (190°C). Pipe 5- to 6-inch strips of dough into the hot oil using a sturdy pastry bag fitted with a medium star tip. Do not overcrowd the oil. Fry until golden; drain on paper towels.
Combine 1/2 cup sugar and cinnamon. Roll drained churros in cinnamon and sugar mixture.