Heat water, butter, sugar, vanilla and salt in a medium-size saucepan until simmering and butter has melted.
Remove from heat and dump in flour all at once. Mix vigorously with a spoon until the mixture forms a smooth ball and no floury bits are visible.
Let cool 5 to 10 minutes, then add eggs, one at a time. Beat them in with a large whisk or use a hand- or stand mixer.
Transfer churros to a pastry bag or strong gallon ziploc bag with a corner snipped off, fitted with a large closed star tip.
Pipe the churros in 6-inch lengths into the oil, or pipe them onto a baking sheet lined with parchment paper and refrigerate for 15 minutes to a couple of hours.
Heat oil in a Dutch oven or cast iron skillet until it measures about 1 ½ inches deep and heat over medium/medium-high heat to 375 degrees.
Gently drop a few churros at a time into the oil and fry until deep golden brown on all sides, about 6 minutes.
Remove from oil and drain on towels for a minute before transferring to a tray in the oven to keep warm.
Combine cinnamon and sugar on a plate and roll warm churros in the mixture to coat.
Heat cream, chocolate and salt in a bowl in microwave in 30 second bursts, whisking until chocolate has melted.
Dip warm churros in warm chocolate sauce.
