Preheat the oven to 350 degrees Fahrenheit and line baking sheet with parchment paper or with silicone baking mats.
In a medium sized saucepan, combine the sugar, butter, milk and water. Bring the mixture to a small simmer.
Once the sugar and butter mixture have started to simmer, add the flour and mix continuously so that it doesn’t stick to the bottom of the pan.
Carefully transfer the dough to a stand mixture and with a paddle attachment and mix on low for 2-3 minutes. While the dough is mixing, start adding in the eggs one at a time. Make sure to allow the eggs to completely mix before adding in the next egg to the mixture. Once the eggs have been combined with the dough, add the vanilla and salt then mix the dough for an additional 2-3 minutes.
Transfer the dough to a bag for piping out the eclair pastry onto the prepared baking sheet. Add a medium sized round tip (I used a Wilton size 199). Pipe them about 5 inches long.
Once all of the eclairs are piped, place them into the oven and bake for 35 to 40 minutes, or until they start to brown and look glossy. DO NOT OPEN THE OVEN DOOR DURING BAKING. This can ruin the eclairs.
Once baked, piece an eclair with a toothpick and make sure they are hollow. If not hollow, bake for an additional 5 minutes.
Allow the pastry to cool before filling with cream.
Classic Cream Filling
Add the 2 cups of milk and 1/4 cup of granulated sugar to a medium saucepan over medium heat and bring the mixture to a simmer.
In a large bowl, whisk together the egg and egg yolks. Add in the 1/3 cup sugar and cornstarch and mix until smooth. Add in the simmering milk and sugar to the bowl and continue to whisk while slowly combining the two.
Return the milk and egg mixture to the saucepan and slowly bring these to a boil while continuously stirring.
Once the mixture starts to boil and thicken, remove it from the heat. Stir in the vanilla and butter.
Pour the mixture into a heat safe container. (I used a glass measuring cup.) Use the plastic wrap to cover the cream by pushing the plastic down to touch the top of the cream so that when cooling a film doesn’t form on the top of the cream.
Place the covered bowl into the refrigerator and allow to cool before piping into the eclairs.
Chocolate Glaze
In a medium bowl, melt the chocolate in the microwave. Whisk in the butter until smooth.
Assemble the Eclair
Make the cream first so that it has time to cool while you’re making the eclair pastry.
Allow the eclair pastry to fully cool before filling with the cream.
To fill the pastry, use a bag and piping tip or a pastry filling tool to fill the eclairs with cream.
Prep the chocolate glaze.
Dip the eclairs into the chocolate glaze and place on a plate to allow the glaze to cool before serving.
Notes
This recipe makes about 12 to 18 eclairs, depending on their size. Store leftover eclairs in an airtight container at room temperature for up to 3 days.