Ice cream toppingschocolate, caramel, or honey would be good; optional
In a medium saucepan, combine butter, brown sugar, salt, and water. Turn up the heat to medium-high. As soon as the butter has fully melted and the mixture begins to boil, reduce the heat to low and add in flour. Using a wooden spoon, stir until the dough comes together to form a ball (about 1 minute). Remove from heat and let cool for 5 minutes (to prevent accidentally cooking the eggs).
Mix in the vanilla extract and add in the eggs, one at a time, being sure to fully incorporate each egg before adding the next. Once all the eggs are mixed in, transfer the dough to a piping bag with a star tip.
Invert a muffin tin and spray thoroughly with nonstick cooking spray. Pipe the dough around the inverted cups in spirals to form the bowls. Immediately transfer the tray to the freezer and freeze until solid (about 3 hours or overnight).
Heat oil in a deep pot to 350°F (175°C). Remove the muffin tin from the freezer and flex it to release the churro bowls or use a small knife under the bottom edge to carefully release them. Return extras to the freezer while you fry so they don't thaw too much.
Fry them in batches of 2-3 at a time, until nicely browned. Be sure to roll them in the oil so they are cooked inside and out. Once they become a medium brown color, remove them from the oil to a plate lined with a paper towel. Dab off any excess oil with more paper towels, then roll them in cinnamon sugar, coating all sides. Shake to remove excess cinnamon sugar.
Fill the bowls ice cream and your favorite toppings
Other equipment needed: Piping bag with a small or medium star tip Muffin tin (12 cups)