Preheat the oven to 375° and line 2 baking sheets with parchment paper. Arrange racks in the upper and lower thirds of the oven.
In a food processor, combine the almond paste, sugar, cocoa powder and salt and process until the almond paste is very finely chopped. Add the egg whites and process until smooth. Add the chocolate chips and pulse just until incorporated.
Transfer the batter to a pastry bag fitted with a 1/2-inch plain tip. Pipe half of the batter 2 inches apart on the prepared baking sheets in slightly rounded teaspoons (about 1 inch in diameter). Alternatively, use a spoon to dollop the batter. Generously sprinkle the cookies with pearl sugar or pignoli.
Bake the cookies for 13 to 14 minutes, until risen and lightly cracked but still soft, shifting the pans from top to bottom and front to back halfway through. Slide the paper onto racks and let the cookies cool completely on the paper. Let the baking sheets cool completely, line with fresh parchment paper and repeat with the remaining batter. Invert the parchment onto a work surface and peel it off the cookies.
The cookies can be stored in an airtight container overnight.