Stir in enough boiling water to make a glaze of spreading consistency set aside. In a medium mixing bowl combine confectioners' sugar and vanilla.
Fold whipped cream into warm pastry cream. In a small mixing bowl beat whipping cream until soft peaks form. Cover surface with plastic wrap and cool just until warm without stirring. Slowly stir about half of the hot mixture into beaten egg yolks. Cook and stir over medium heat until mixture is thickened and bubbly. Slowly stir in half-and-half or light cream. In a heavy, medium saucepan stir together sugar, flour, and salt. (Or bake according to package directions.) Carefully remove pastries from baking sheet. Bake in a preheated oven for 18-23 minutes, or until golden.
Transfer pastry squares to the prepared baking sheets prick pastry. Unfold puff pastry sheet and trim edges to a 9-inch square. Line 2 baking sheets with parchment paper or plain brown paper set aside.
