In a small bowl, toss together walnuts, 2 Tbs. sugar, and cinnamon. Unroll piecrust and spread whipped cream cheese on top. Sprinkle the walnut mixture over the cream cheese, then slice dough into 16 wedges (a pizza cutter works well). Starting at the outside edge, roll each wedge toward the point. Transfer the rugelach to a parchment-lined baking sheet. Brush the tops with egg wash (egg whisked with water) and sprinkle with ½ Tbs. sugar. Bake at 350°F until dough is puffy and golden brown, about 20 minutes.