Combine water, 2 tablespoons sugar, salt, and butter in a saucepan and bring to a boil over medium heat.

Remove from heat, add flour all at once, and stir vigorously with a wooden spoon until a smooth ball of dough forms.

Transfer the dough to a piping bag fitted with a large star-shaped nozzle.

Heat vegetable oil in a deep pot to 350°F (175°C). Use a thermometer to ensure the oil is at the correct temperature for even cooking.

Carefully pipe 4-6 inch strips of dough directly into the hot oil, using kitchen shears to cut the dough. Fry churros in batches until golden brown and cooked through, about 2-3 minutes per side. Drain on a paper towel-lined plate.

Mix the remaining 1/2 cup sugar with cinnamon in a shallow dish. While still warm, roll the fried churros in the cinnamon sugar mixture until evenly coated.

Serve the churros immediately with your favorite dipping sauce, such as chocolate or dulce de leche.