In a saucepan, combine water, sugar, salt, and butter. Bring to a boil until butter melts, then remove from heat and stir in flour. Stir until the dough pulls away from the pan.
- Let the dough cool for a few minutes, then add eggs one at a time, mixing well. Stir in vanilla.
- Heat oil to 350°F (175°C) in a frying pan. Pipe dough into 4-6 inch strips and fry in batches for 2-3 minutes, until golden brown. Remove and drain on paper towels.
- Roll churros in cinnamon-sugar while still warm. Serve with chocolate dipping sauce or enjoy plain.
- For the chocolate sauce, heat heavy cream in a saucepan and add chopped chocolate. Stir until smooth, adding sugar and vanilla if desired. Keep warm.