Dough can be made 5 days ahead. Keep chilled. Let stand at room temperature for 30 minutes before continuing.
Arrange a rack in center of your oven and preheat to 180°. Line a baking tray with baking paper. Remove plastic wrap from dough. Cut out desired shapes (I did circles). Using the back of a teaspoon schmear cookies with nutella, then sprinkle with salt.
Bake, rotating tray halfway through, until cookies are slightly darker (chocolate cookies are trickier to tell when ready, so keep a close eye on the time & a slight colour change as an indication), 12–14 minutes. Let cool on tray for at least 10 minutes. Serve warm or at room temperature.