Bring the first four ingredients to a boil in a small pot
Remove from the heat and add the flour all at once, stir well with a wooden spoon
Put the pot back on medium speed, keep stirring with a wooden spoon till it comes together - about a minute.
Transfer the dough to a mixing bowl, let it cool for a few minutes.
Add your eggs one by one beating well until the dough comes together to create something that is cohesive and shiny. When you lift your beater up you will see thick ribbons forming.
Preheat the oven to 425 degrees F.
Draw lines on a parchment paper (I used a credit card!) making sure to space them 2.5 inches apart and then flip the parchment paper
Put your dough into a piping bag with a 1.5-2.5 cm opening depending on how thick you want the final result.
Pipe lines (you can trim the ends with a knife as you pipe)
Bake for 16-18 minutes for slim eclairs, 20 minutes for thicker ones. The pastry cases should look a deep golden and feel hollow when you tap them. TIP: For a humid environment pile all your finished cases on to one sheet, turn the oven off and leave them in for a few extra minutes.
Heat the cream to barely simmering, stir in chocolate chips to melt, set aside to cool (and thicken)
Start whipping the cream on medium heat
As it thickens then add the sugar gradually until stiff peaks form
Mix in the Vanilla, adjust for taste adding in more sugar if needed.
Fill your cream into a piping bag with a metal tip (I use my star tip)
Use the tip to poke a hole into the side of the case
Apply pressure to fill the hollow case with cream
Dip the tops of the eclairs in your glaze (if it is too runny refrigerate it for a little bit, if it is too hard then warm it a little).
If you do not have a piping bag with a metal tip then you can cut a slit into the side of your eclair cases and use a ziploc bag with a hole cut in it to fill the eclairs.