Preheat your oven to 400°F (200°C). Line two large baking sheets with parchment paper.

In a medium saucepan, combine water, butter, salt, and 1 tablespoon of granulated sugar. Bring the mixture to a rolling boil over medium heat, stirring occasionally to melt the butter.

Remove the saucepan from the heat. Add all the all-purpose flour at once. Stir vigorously with a sturdy wooden spoon until the mixture forms a ball of dough that pulls away cleanly from the sides of the pan.

Return the saucepan to low heat and continue to cook, stirring constantly, for 1-2 minutes. This step helps dry out the dough, which is crucial for a good churro texture.

Transfer the dough to a large mixing bowl. Let it cool for about 5 minutes, stirring occasionally, to prevent the eggs from scrambling.

Add the eggs one at a time, beating well with an electric mixer (or by hand, though it will take more effort) after each addition, until the egg is fully incorporated and the dough is smooth and glossy. Finally, stir in the vanilla extract.

Transfer the churro dough to a piping bag fitted with a large star tip. Pipe 4-5 inch long churros onto the prepared baking sheets, leaving about 1 inch of space between each. Use scissors or a knife to cleanly cut the dough from the tip.

Bake for 18-22 minutes, or until the churros are golden brown, puffed, and firm to the touch.

While the churros are baking, combine 1/2 cup granulated sugar and ground cinnamon in a shallow dish or plate.

As soon as the churros come out of the oven, brush them lightly with melted butter (if using) and immediately roll them in the cinnamon-sugar mixture until evenly coated.

Serve the baked churros warm, ideally with chocolate dipping sauce or dulce de leche for an extra treat.