1In a saucepan, bring water, butter, and salt to a boil. Remove from heat, add the sifted flour all at once, and stir vigorously until combined.
2Return the saucepan to low heat and cook the dough for 2 minutes, stirring constantly, until it dries out. Let it cool slightly.
3Add the eggs one at a time, mixing well after each addition, until the dough is smooth and glossy.
4Transfer the dough to a piping bag and pipe small balls onto a parchment-lined tray.
5Cook in the air fryer at 180°C (350°F) for 12 minutes, until golden brown and puffed.
6In a small saucepan, melt the dark chocolate with the heavy cream over low heat. Stir in the optional butter for a shiny finish.
7Cut the profiteroles open, fill with vanilla ice cream, and drizzle with warm chocolate sauce.