Prepare a plate with paper towels on top.
Heat the oil to 175-180 °C. If you don’t have a thermometer, check if the oil is ready by frying a piece of prepared dough, or bread. If the oil starts sizzling around it, it’s ready and if not, wait for a bit more and repeat the test.
Hold the piping bag a few cms from the oil, squeeze out the dough and break it off with scissors or a knife after the desired length.
When you notice churros browning on the bottom turn them once and fry the other side. When they are nicely browned, lift them out and put onto your prepared plate.
Roll your churros in cinnamon sugar or sprinkle them with powdered sugar.
For the chocolate sauce, just melt the chocolate over a bain-marie or microwave. You can also prepare your favorite chocolate sauce or ganache or caramel sauce for dipping the churros in.