*If it's your first time making eclairs, I suggest you read all the notes above to avoid any mistakes and troubleshooting.
If you haven't made the Pastry Cream already, do that first, so it has time to chill in the fridge.
Preheat the oven to 390F (200C), without the fan.
Line a baking tray with a silicone mat, perforated mat, or parchment paper.
Add water, butter, sugar, and salt to a saucepan over med heat.
Meanwhile, whisk the eggs.
Once the milk starts boiling and everything is melted add the flour all at once. Mix it in and keep steering till it thickens and forms a thin layer on the bottom of the pan.
Take off the heat and transfer to a bowl of the stand mixer with a paddle attachment, you can use a hand mixer as well. Spread the dough in the bowl so it can cool off faster. Wait for a few minutes before the next step.
With the mixer running, start adding the whisked eggs, a little at a time. The dough will look chunky at first, but very quickly it will become smooth and glossy. When you add about half of the eggs stop and check the consistency of the dough. Be careful towards the end, you might not need to add all the eggs. The dough is ready when it slowly falls down from the paddle attachment in a V-shape.
Once the dough is ready, transfer it a piping bag with a French Tip nozzle on it. If you don't have a french tip, you can use just a round one, but after you pipe them run a fork over them to create the needed texture for the eclairs to expand without cracking.
Pipe each eclair it a 45° with the edge of the tip touching the surface for support. The length of each eclair is about 3.5-4 inches(9-10cm). Leave enough space between each eclair as they will expand when baking. When piping the eclairs it will create a tip at the end of each one (see images). Do not leave it as it can burn when baking. You can smooth it out easily by using a wet finger.
Right before baking turn the oven to 350F (180C). Bake on the middle rack for about 40-45 min. Do not open the oven in the first 30 minutes, not until they are puffed and golden brown.
Take them out of the oven and transfer to a cooling rack. Once cooled, fill them with pastry cream.
If you would like to top them off with chocolate and nuts, melt some chocolate over a double boiler, dip each eclair in the melted chocolate and sprinkle some nuts of your choise.
Best served the same day. Store them in an airtight container in the fridge or you can freeze them for longer.