This detailed recipe will guide you through the process of making delicious chocolate eclairs, complete with choux pastry, a rich filling, and smooth chocolate icing. Follow these steps to achieve perfect eclairs every time.

**Ingredients:**

**Choux Pastry:**

- 1 cup water

- 1/2 cup butter

- 1 cup all-purpose flour

- 1/4 teaspoon salt

- 4 large eggs

**Filling:**

- 2 1/2 cups cold milk

- 1 (5-ounce) package instant vanilla pudding mix

- 1 cup heavy cream

- 1/4 cup confectioners’ sugar

- 1 teaspoon vanilla extract

**Icing:**

- 2 (1-ounce) squares semisweet chocolate

- 2 tablespoons butter

- 1 cup confectioners’ sugar

- 1 teaspoon vanilla extract

- 3 tablespoons hot water

**Instructions:**

**1. Preheat and Prepare:**

- Preheat the oven to 450°F (230°C). Grease a cookie sheet and set aside.

**2. Make the Choux Pastry:**

- In a medium pot, combine water and butter. Bring to a boil, stirring until the butter melts completely. 

- Reduce heat to low and add flour and salt. Stir vigorously until the mixture forms a stiff ball and leaves the sides of the pan. Remove from heat.

- Add eggs one at a time, beating well after each addition until fully incorporated.

- Using a spoon or a pastry bag fitted with a No. 10 or larger tip, pipe or spoon dough onto the prepared cookie sheet in 1 1/2×4-inch strips.

**3. Bake the Choux Pastry:**

- Bake in the preheated oven for 15 minutes.

- Reduce heat to 325°F (165°C) and continue baking until the bottoms sound hollow when lightly tapped, about 20 more minutes.

- Cool completely on a wire rack.

**4. Make the Filling:**

- In a medium bowl, combine milk and pudding mix according to package directions.

- In a separate bowl, beat heavy cream with an electric mixer until soft peaks form. Beat in confectioners’ sugar and vanilla extract.

- Fold the whipped cream into the pudding mixture.

**5. Assemble the Eclairs:**

- Cut the tops off the cooled pastry shells with a sharp knife.

- Fill the shells with the pudding mixture and replace the tops.

**6. Make the Icing:**

- In a medium saucepan, melt chocolate and butter over low heat.

- Stir in confectioners’ sugar and vanilla extract. Gradually add hot water, 1 tablespoon at a time, until the icing is smooth and reaches the desired consistency.

- Remove from heat and cool slightly.

**7. Ice the Eclairs:**

- Drizzle or spread the chocolate icing over the filled eclairs.

- Store in the refrigerator until ready to serve.

**Enjoy your homemade classic chocolate eclairs!**

**Tips and Troubleshooting:**

- **Choux Pastry:** If the dough is too runny, it may need more flour. If it’s too thick, it may need an extra egg. Ensure it forms a smooth, shiny ball.

- **Baking:** If the eclairs deflate after baking, it could be due to underbaking or opening the oven door too early. Make sure to bake them fully and resist the urge to check too soon.

- **Filling:** Ensure the pudding mixture is well-set before filling the eclairs to avoid a runny filling.

- **Icing:** Adjust the amount of hot water in the icing to get the right consistency—thick enough to coat but thin enough to drizzle.