For the profiteroles: Preheat the oven to 425 degrees F.
In a small saucepan, combine 1/2 cup water, the butter and the salt and bring to a boil. Reduce the heat, add the flour all at once and stir it vigorously with a wooden spoon. Cook until the mixture has formed a ball with a slightly sweaty sheen to it, and has pulled away from the pan. Transfer 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 one 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 baking sheet lined with parchment paper. Be sure to leave at least 1 inch between each of the balls¿they grow! When done, dip your finger in water and smooth the top of each ball where the pastry bag released the dough. Bake in the preheated oven for 20 to 25 minutes, rotating the baking sheet halfway through to ensure even cooking. When done, the puffs should be light, airy and dry inside. Cool on a rack.
For the chocolate sauce: Fill a saucepan with 1 inch of water and bring to a boil. Put the chocolate in a metal or heatproof glass mixing bowl and place on top of the saucepan with the boiling water. Pay careful attention that the mixing bowl does not touch the surface of the boiling water. Add the cream, butter, corn syrup and cinnamon 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.
When ready to serve, cut the profiteroles in half horizontally and fill them with ice cream. Top with warm chocolate sauce.