Mix the cinnamon sugar in a shallow bowl. In another bowl, whisk together the flour, salt, and sugar.
In a small pot over medium-high heat, bring the water and butter to a boil. Once the butter melts, turn off the heat.
Add the flour mixture all at once. Mix until no dry flour remains and the dough pulls away from the pot.
Stir briefly to cool the dough slightly. Add the egg while the dough is still warm. Mix until smooth.
Transfer to a sturdy piping bag fitted with a large star tip. Press out any air pockets.
Heat 1 inch of oil in a deep, wide pot to 350°F. Without a thermometer, test with a small piece of dough — it should sizzle and float.
Pipe strips into the oil, snipping with kitchen scissors. Fry in small batches until golden on all sides, turning as needed. Cut one open from the first batch to check for raw dough.
Drain briefly on paper towels. Roll in cinnamon sugar while warm.
Combine the cream, tablea, and sugar in a microwave-safe bowl. Microwave in 20-second intervals, stirring each time, until smooth. Add more cream if needed. Serve warm with the churros.