Preheat oven to 300 degrees F. Line 2 baking sheets with parchment paper or spray with Pompeian Grapeseed Oil Spray.
Break the almond paste into small pieces; place the pieces in a food processor. Add the granulated and confectioner's sugars, salt, and the flour. Pulse until the mixture is finely ground. Begin to add the egg whites, a little at a time, just until the dough comes together. You may not need to add all of the egg whites.
With slightly wet hands, roll the dough into 1-inch balls. I recommend scooping them out with a small cookie scoop, to keep them uniform. You're going to get 12 - 15 cookies from this recipe. Roll the balls in the pine nuts, pressing to adhere the nuts (mainly on the tops of the cookies.)
Place the balls 2-inches apart on the prepared baking sheet. Slightly flatten the tops of the cookies with your fingers. Bake 15-20 minutes or until golden brown. Remove from the oven, and allow cookies to cool completely on the baking sheets.
When cooled, dust cookies generously with confectioner's sugar before serving.