For the eclairs: Preheat the oven to 375 degrees F with a rack on the middle shelf.
In a non-reactive saucepan over medium heat, combine the milk, salt, sugar and butter, and bring to a simmer. Once the butter has melted, quickly add the flour and stir constantly with a wooden spoon for about 3 minutes.
Transfer to the bowl of a stand mixer fitted with a paddle attachment. Mix to cool down, until the dough mostly stops steaming, 1 minute. Add the eggs and whites, slowly until evenly incorporated and glossy. To check the consistency of the batter, run your finger or spoon through it. It should leave a pathway that slowly falls in on itself. If it's too stiff, you may have to add an additional egg.
Place the batter in a pastry bag or resealable plastic bag and cut a hot-dog-size hole in the corner. On a silicon-lined sheet tray, pipe long and fat hot-dog-size lines about 6-inches long, evenly spaced. Use a wet finger to press down any peaks and lightly mist with water from a spray bottle. Bake until slightly golden and puffed, 20 minutes.
Then lower the oven temperature to 325 degrees F and bake an additional 20 minutes.
For the whipped cream: In a stand mixer fitted with a whisk attachment, whisk the cream, confectioners' sugar and almond extract until stiff peaks form.
For the glaze: Heat the cream in a small pot until slightly simmering. Pour over the chocolate in a metal bowl and whisk until smooth. If there are still chocolate chunks in the glaze, heat it briefly on the stovetop and stir until smooth. Set aside.
To assemble: Split the baked pastry and, using a resealable plastic bag or pastry bag with a 1/2-inch hole cut in the corner, pipe in the almond filling. Top with the chocolate glaze, crushed roasted almonds, and a couple pinches of smoked sea salt.