1. Make cinnamon sugar: In a shallow dish, mix together the ½ cup sugar and cinnamon until well combined. Set aside near your frying station for easy coating.
2. Prepare piping bag: Fit a large piping bag with a large star tip (1M size works great). Twist the bag just above the tip and tuck it inside to prevent leaking while you fill it. Set aside.
3. Heat water mixture: In a medium saucepan, combine the water, butter, 1 tablespoon sugar, and salt. Place over medium-high heat and bring to a full rolling boil, stirring occasionally to help the butter melt evenly.
4. Add flour: As soon as the mixture reaches a rolling boil, remove from heat and immediately add all the flour at once. Stir vigorously with a wooden spoon until the mixture forms a ball and pulls away from the sides of the pan. This should take about 1 minute of stirring. The dough will look shaggy at first but will come together.
5. Cool slightly: Let the dough cool for about 3-4 minutes. It should be warm but not so hot that it will cook the eggs. You should be able to hold your hand on the outside of the pan comfortably.
6. Add eggs: Add the eggs one at a time, stirring vigorously after each addition. The dough will look like it’s separating and won’t come together at first—this is normal! Keep stirring and it will become smooth and glossy. After the second egg is fully incorporated, stir in the vanilla extract.
7. Fill piping bag: Transfer the warm dough to your prepared piping bag. Untwist the bag from the tip and push the dough down, squeezing out any air pockets. Twist the top of the bag to seal.
8. Heat oil: Pour about 2-3 inches of vegetable oil into a heavy-bottomed pot or deep fryer. Heat over medium-high heat until the oil reaches 375°F (190°C) on a cooking thermometer. This temperature is crucial—too low and churros will be greasy; too high and they’ll burn before cooking through.
9. Pipe and cut: Carefully pipe 4-5 inch strips of dough directly into the hot oil, using kitchen scissors or a knife to cut the dough from the piping tip. Don’t overcrowd—fry only 3-4 churros at a time to maintain oil temperature.
10. Fry until golden: Fry churros for 2 minutes on the first side until deep golden brown, then flip and fry for another 1-2 minutes on the second side. They should be dark golden brown and crispy. Use a slotted spoon or spider strainer to carefully turn them.
11. Drain and coat: Remove churros from oil and let them drain on paper towels for just 10-15 seconds—you want them still hot for coating. Immediately roll the hot churros in the cinnamon sugar mixture, coating all sides generously. The sugar will stick to the hot churros perfectly.
12. Serve warm: Serve churros immediately while still warm and crispy. They’re best enjoyed within the first 30 minutes of frying.

For Chocolate Sauce (Optional): Heat heavy cream until just simmering, pour over chopped chocolate, let sit 1 minute, then stir until smooth. Stir in vanilla. Serve warm with churros for dipping.