Preheat the oven to 325°F (160°C). Line a baking sheet with parchment paper.
Crumble the almond paste into the bowl of a food processor. Pulse until finely ground. Add confectioners’ sugar and salt and pulse until combined.
In a large bowl, beat the egg whites until frothy, about 2 minutes. Pour the frothy whites into the food processor bowl, add the almond extract and almond flour, and pulse until smooth. Give the almond flour 5 minutes to absorb moisture, and pulse one more time.
Place pine nuts in a shallow bowl. With a tablespoon-size measuring cup, scoop chunks of dough and shape them into balls. Flatten each ball in pine nuts, coating each side, then place the cookies on the prepared baking sheet.
Bake the cookies until the edges are golden, about 20 minutes. Keep them in another few minutes if you prefer crispy cookies. Let the cookies cool completely on the baking sheet. They will firm up as they cool.
The pignoli cookies can be kept for up to three days in an airtight container at room temperature, and frozen for up to one month. Defrost them at room temperature.