Step 1: Prepare the Churro Dough

1. Heat the Water and Butter: In a medium saucepan, combine the water, butter, sugar, and salt. Heat over medium heat, stirring occasionally, until the butter melts and the mixture comes to a simmer.
2. Add the Flour: Once the water-butter mixture is simmering, add the flour all at once. Stir quickly with a wooden spoon or silicone spatula to combine. Continue to cook the mixture for about 1-2 minutes, until the dough pulls away from the sides of the pan and forms a ball.
3. Cool the Dough Slightly: Remove the pan from the heat and let the dough cool for a few minutes. This is important so that the eggs don’t cook when added.
4. Incorporate the Eggs: Once the dough has cooled slightly, add the eggs, one at a time. Stir vigorously after each addition to incorporate them fully. The dough will initially seem sticky but will come together into a smooth, cohesive mixture.
5. Add the Vanilla: Stir in the vanilla extract for added flavor. The dough should be smooth, soft, and slightly sticky but hold its shape when piped.

Step 2: Prepare the Chocolate Dipping Sauce

1. Melt the Chocolate: In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer (don’t let it boil). Remove from heat and add the chopped semisweet chocolate, stirring until it’s fully melted and smooth.
2. Sweeten the Sauce: Stir in the granulated sugar and vanilla extract until well combined. The sauce should be creamy and slightly thickened, perfect for dipping.
3. Keep Warm: Transfer the chocolate sauce to a serving dish and cover to keep warm while you prepare the churros.

Step 3: Heat the Oil for Frying

1. Heat the Oil: In a deep frying pan or Dutch oven, pour enough vegetable oil to fill the pan about 3-4 inches deep. Heat the oil over medium-high heat until it reaches 350°F (175°C). Use a thermometer to ensure the oil is at the correct temperature—too hot, and the churros will burn; too cold, and they will be greasy.

Step 4: Pipe and Fry the Churros

1. Prepare the Piping Bag: Fit a large piping bag with a star tip (such as a #1M or #2D). Fill the piping bag with the churro dough, making sure it’s secure and there are no air pockets.
2. Pipe the Churros: Once the oil is hot, carefully pipe 3-4 inch long churros into the oil. Use scissors or your hands to cut the dough after each churro, creating the desired length.
3. Fry the Churros: Fry the churros in batches, being careful not to overcrowd the pan. Fry them for about 2-3 minutes on each side, or until they are golden brown and crispy. Use a slotted spoon to transfer the churros to a paper towel-lined plate to drain excess oil.

Step 5: Coat the Churros

1. Cinnamon Sugar Coating: While the churros are still warm, roll them in the cinnamon sugar mixture, making sure each one is fully coated. The cinnamon sugar will stick perfectly to the churros, adding that classic sweetness.

Step 6: Serve the Churros

1. Serve Immediately: Serve the churros while they’re still warm and crispy, alongside the chocolate dipping sauce. Dip each churro into the sauce for a decadent experience!