Crispy fried dough dusted in cinnamon sugar is Mexico's most beloved street dessert. These golden, crunchy treats are a family favorite perfect for sharing at fiestas and gatherings.
In a medium saucepan over medium-high heat, combine water, unsalted butter, and salt; bring to a boil, ensuring the butter is fully melted.
Reduce heat to low and add all-purpose flour at once. Stir vigorously until dough forms a smooth ball that pulls away from the sides (about 2 minutes).
Remove from heat and let dough cool for 5 minutes before beating in large eggs one at a time, mixing thoroughly after each until glossy and cohesive.
Transfer dough to a pastry bag fitted with a large star tip for maximum ridged texture.
Heat vegetable oil in a heavy pot to 350°F (175°C), monitoring temperature with a thermometer.
Pipe dough strips (about 5-6 inches) directly into hot oil. Fry in batches without overcrowding, turning occasionally until golden and crisp (about 2-3 minutes per batch).
Drain churros on paper towels briefly, then immediately roll in a mixture of sugar and ground cinnamon while still warm to ensure coating adheres.
Serve hot for best texture.