Special equipment: Pastry bag fitted with large straight tip
Preheat oven to 425 degrees F.
In a small saucepan combine the water, butter and salt and bring to a boil. Reduce the heat and add the flour all at once and stir it vigorously with a wooden spoon. Cook until the mixture has formed a ball and has a slightly sweaty sheen to it and it has pulled away from the pan. Transfer the mixture to a mixing bowl and let cool for 3 to 4 minutes. The mixture does not have to be cold, just cool enough not to cook the eggs when added. Using an electric mixer or lots of good old-fashioned elbow grease, beat in the eggs 1 at a time. Do not add the second egg until the first is fully incorporated. Add in the cinnamon and beat for another second to combine.
Transfer the mixture to a pastry bag equipped with a large straight tip and pipe 1-inch balls onto a sheet tray lined with parchment paper. When done dip your finger in water and smooth the top of each ball where the pastry bag released the dough. Be sure to leave at least 1-inch between each of the balls. They grow! Bake in the preheated oven for 20 to 25 minutes, rotating the tray halfway through the cooking time to insure even cooking. When done, the puffs should be light, airy and dry inside. Cool on a rack.
When ready to serve, cut in half horizontally and fill with ice cream of your choosing. (I prefer a really high-quality vanilla.) Top with warm Chocolate Sauce.
Bring a saucepan with 1-inch of water to a boil. Put the chocolate in a metal or heatproof glass mixing bowl and place on top of the saucepan with boiling water. Pay careful attention that the mixing bowl does not touch the surface of the boiling water. Add the rest of the ingredients and stir until the chocolate has melted and everything is combined. This is a pretty quick process, once the chocolate has melted remove it from the double boiler set up. Spoon over the filled profiteroles. This is best when served warm!