Heat oven to 375°F.
Melt butter in nonstick skillet over medium heat. Add apples, walnuts, sugar and cinnamon; cook, stirring, 4 minutes, until apples are tender. Let cool.
Separate dough into triangles. Roll out. Place 1 tablespoon apple mixture on wide end of each triangle. Roll up each; gently pinch edges together. Place on ungreased baking sheet.
Bake in 375°F oven for 10 to 12 minutes, until golden. Transfer to rack to cool slightly. Dust with sugar.