Mix flour, sugar, and salt in a bowl.
Add water and butter to a saucepan and bring to a boil.
Add the flour mixture to the boiling water and mix to form a dough.
Once the dough cools, add eggs and mix well.
Transfer the dough to a piping bag.
Pipe dough into oil heated to 170°C and fry.
Place the fried churros on a paper towel to drain excess oil.
Roll the churros in a mixture of sugar and cinnamon powder.