These little treats are sweet way to end an Italian meal.
Preheat oven to 325 degrees. Spread 1 1/4 cups pine nuts and the almonds in a single layer on separate baking sheets. Toast until fragrant and golden brown, about 8 minutes for pine nuts and 10 minutes for almonds. Let cool.
Combine nuts. Process half in a food processor with 3 tablespoons granulated sugar until finely ground. Transfer to a large bowl. Repeat with remaining nuts and 3 more tablespoons sugar, and add to bowl. Stir in orange zest and salt.
Beat 2 egg whites until fluffy. Gradually add remaining 2 tablespoons sugar and the vanilla, and beat until stiff peaks form. Fold into nut mixture.
Using 2 teaspoons batter for each cookie, shape into balls, and place on parchment-lined baking sheets. Brush tops with egg white, and sprinkle with sanding sugar. Press 2 pine nuts into top of each cookie for garnish.
Bake until edges are golden and centers are set, about 17 minutes. Let cool on sheets for 10 minutes, then transfer cookies to wire racks to cool completely.