Thaw the pastry sheets at room temperature for 40 min. or until they're easy to handle. Heat the oven to 375 degrees F. Beat the egg yolks and water in a cup with a fork.

Unfold 1 pastry sheet on a lightly floured surface. Roll the sheet into a 16" square. Brush the pastry lightly with some of the egg mixture. Cut the pastry sheet into 16 (4") squares.

Put 1 tsp. chocolate pieces onto the center of each square. Fold the pastry over the filling to form a triangle and press the edges together to seal. Press the sealed edges with the tines of a fork. Prick the center of each triangle. Repeat with remaining pastry and chocolate pieces. Put triangles on a shallow-sided baking pan. Brush triangles with egg mixture. Freeze triangles for 15 min. or until firm. Put triangles on 2 ungreased baking sheets.

Bake for 15 min. or until the triangles are puffed and golden. Remove the triangles from the baking sheet and cool slightly on wire rack. Sprinkle triangles with confectioners' sugar. Serve warm.

Chocolate-Raspberry Triangles: Put 1 fresh raspberry with the chocolate pieces on the center of each pastry square before folding.