Unfold pastry sheets onto a lightly floured surface. Cut each sheet into nine 3-in. squares. Place 1 in. apart on greased baking sheets; set aside. In a small bowl, beat egg yolk and water; brush over pastry squares. In another bowl, beat egg white; add almonds and sugar. Spread over each square. Bake at 375° for 20-25 minutes or until well puffed and browned. Cool completely on wire racks. Split pastries in half horizontally. Fill with whipped cream; replace tops. Sprinkle with confectioners' sugar. Serve immediately.