Heat the oven to 375. Spray a baking sheet w/ cooking spray. In bowl, stir together brown sugar, flour, cinnamon and nutmeg. Add apples, pecans and butter. Toss to coat.
Unfold pastry sheet onto lightly floured surface. Roll out to a 15" x 10" rectangle. Brush the pastry lightly w/ water. Spoon apple mix onto pastry down the middle of long side of pastry, to w/in 2" of the edges.
Starting at the long side, roll up jelly-roll style. Cut into 12 slices. Place slices, cut side down onto baking sheet. Bake 15 mins or until golden brown. Cool 10 mins. Sprinkle w/ powdered sugar.