In a medium saucepan, combine 1 cup water and 1/2 cup unsalted butter and bring to a rolling boil over medium heat.

Remove the pan from heat and stir in 1 cup all-purpose flour and 1/4 teaspoon salt until a smooth dough forms.

Let the dough rest for 5 minutes to cool slightly.

Beat in 2 large eggs one at a time, mixing well after each addition until the dough is smooth and pliable.

Heat oil in a deep frying pan or Dutch oven to 350°F (175°C) using a cooking thermometer.

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

Pipe 4-inch strips of dough into the hot oil and cut them with scissors to release; fry for 2 to 3 minutes, turning occasionally, until golden brown.

Use a slotted spoon to transfer churros to paper towels to drain excess oil.

In a bowl, combine 1/2 cup granulated sugar and 1 tablespoon ground cinnamon.

Roll warm churros in the cinnamon sugar mixture until evenly coated and serve immediately.