Pâte a Choux (Puff Pastry):
- 1 cup cold water
- 8 Tbsp. (1 stick) butter, cut into small pieces
- ½ tsp. salt
- 1 cup flour
- 4 large eggs
Crême Pâtissier (Pastry Cream):
- 1¾ cups half-and-half
- 4 large egg yolks
- ½ cup sugar
- ⅓ cup flour
- pinch of salt
- 1 tsp. vanilla
Make the puff pastry: Preheat the oven to 475 degrees F. Spray baking sheets with nonstick pray or cover with parchment paper and set aside (you will probably need two, maybe three).
In a saucepan add water, butter and salt. Bring the water to a boil over moderate heat. The butter should be just melted at this point. If the butter is not melted, remove the pan from the heat and wait until the butter has melted. Remove the pan from the heat and add the flour all at once. Stir the mixture with a wooden spoon until the mixture resembles mashed potatoes. Return the pan to medium heat and stir vigorously to dry out the pastry, about 5 minutes. The spoon should be able to practically stand up by itself when you place it upright in the mixture (obviously not if you put it in a place where the mixture is only like an inch high off the pan). When it has dried out enough, remove the pan from the heat and allow the mixture to cool slightly (until it is lukewarm to the touch), about 10 minutes.
Transfer the mixture to a large bowl (recommended but not necessary) and add the eggs one at a time, beating thoroughly to blend. When the eggs are added, it will seem like the pâte a choux will not come together, but just believe me, keep stirring/beating with a wooden spoon. It takes muscle power, but you will get there.
Fit a pastry bag with a large (¾ inch or No. 9) round tip (or just cut out a large hole) and pipe tube shapes onto the greased pans, spacing them about 1½" apart. When you have reached the desired length, keep the tip in place and release the pressure on the bag. Flick the tip down to the sheet and then up, cutting off the pastry as you lift.
Place the pan in the center of the preheated oven and immediately lower the heat setting to 375 degrees F. Bake the pastries until puffed and colored, about 20-25 minutes, then lower the heat to 300 degrees F and bake until dry. Total baking time should be about 40-45 minutes.
Make the pastry cream: Heat half-and-half in a medium saucepan until warm. Set aside (I recommend to just start on the rest of the ingredients while it is warming).
Whisk egg yolks and sugar in a bowl until very thick and pale yellow. Stir in the flour and salt. Gradually add warm half-and-half to yolk mixture. Transfer mixture from bowl to a saucepan and cook over medium-low heat, stirring continuously with a wooden spoon. When mixture begins to bubble, continue stirring for 1-2 minutes (lower heat if necessary). The mixture should be much thicker now (more like a cream).
Remove from heat, add vanilla, and strain into a bowl. To strain, simply place a strainer over a bowl and press down on the bottom of the strainer with a rubber spatula. This mixture should eventually fall through after pressing down several times. Make sure to scrape off whatever stuck to the back of the strainer as well.
Place plastic wrap directly on surface of pastry cream (so that there is no air between plastic wrap and pastry cream) and cut or poke a few holes for the het to escape. Refrigerate until chilled.
Assemble the éclairs: Remove the éclairs from the oven. Poke a small hole in each end, using a small pastry tip, a skewer, or the tip of a small knife, and cool completely on a rack. Once cooled, pipe the pastry cream into the éclairs from each end. Dip in melted chocolate if preferred.