Arrange one rack in the upper third of the oven
and the other in the lower third. Preheat the oven to 350 F. Line two baking
sheets with parchment paper, or grease them lightly.
Crumble the almond paste into a mixing bowl. Beat with
a handheld electric mixer till crumbled fine. Sprinkle the sugar over the
almond paste while continuing to beat, until the sugar is incorporated.
Beat in the egg whites, one at a time, and continue beating until the dough
is smooth. (The batter can be formed into cookies and baked at this point,
or wrapped in plastic wrap and refrigerated for up to 1 day.)
Spread the pine nuts out on a plate. Roll 1 tablespoon
of the dough into a ball between your palms. Drop the dough ball onto the
plate of pine nuts. When you have formed several dough balls, roll them
in the pine nuts to coat lightly on all sides. Transfer them to the prepared
baking sheets and press them lightly, to flatten them slightly and help
the pine nuts adhere to the cookies. Repeat with the remaining batter and
pine nuts.
Bake the cookies until lightly browned and soft and springy,
about 15 minutes. Remove, and cool, completely on wire racks before serving.
The cookies can be stored in a covered container at room temperature for
up to a week.