Preheat the oven to 350F. Line two baking sheets with parchment paper. Set aside. Prep a pastry bag with a round tip on the end. If you don't own a tip, no biggie, it's not totally necessary.
In a medium saucepan, set over medium heat, add the butter, sugar, salt and water. Bring to a gentle boil. Do not allow the water to boil for any length of time or it will begin to evaporate, and the proportion of liquid to dry ingredients will change, compromising the final dough. Once boiling, immediately remove the pan from the heat and, using a spatula, quickly mix in the flour.
Return the saucepan to medium heat and continue beating in the flour for 30 seconds. The mixture should begin to thicken, dry out and form a mass. A think film should form on the bottom of the pan and the mixture should begin to pull away from the sides of the pan.
Using a rubber spatula, scrape the mixture into the bowl of a standing electric mixer fitted with the paddle. Begin beating the paste at medium-low speed to release some steam and to allow it to cool somewhat. I did this for about 1 minute.
Pour in one egg at a time, beating continuously until the paste is smooth and shiny. The dough will go from sloshy to smooth and will eventually be smooth and fall on itself.
Transfer the choux to the prepared pastry bag. Pipe out about 9 profiteroles per baking sheet, spacing them about 2-inches apart. Note: If there are any little tips to any of the profiteroles, you can dip your finger in water and lightly pat them down.
Using a pastry brush, lightly coat each piece with egg wash, Place baking sheet in oven and turn oven temperature to 425F bake for 15 minutes.
At the 15-minute mark, turn oven temperature down to 350F and bake for another 10 minutes, until nice and golden brown. If they're starting to get too dark then remove them. Transfer to a cooling rack. Take a small paring knife and pierce a small hold on the sides--this will let out any moisture. Allow them to cool for 15 minutes.
To Make the Chocolate Sauce:
While the cream puffs are cooling, let's make the chocolate sauce. Add the chocolate to a heat-proof bowl. In a small saucepan, heat the heavy cream and butter to a gentle simmer.
Pour the heavy cream over the chocolate; let stand for 1 minute. And then whisk until smooth.
Cut the cream puffs open, place scoops of vanilla ice cream and top with silky smooth chocolate sauce. Yum!