I've had this recipe for several years and never tried it. It got lost in the shuffle. Now that I've re-discovered it, I promise you it will be on the menu very soon.
Recipe: Great American Home Baking
Unfold the pastry sheets on a lightly floured surface. Roll each into a 12x9-inch rectangle. Cut each sheet into twelve 3-inch cutouts.
Place 12 squares on a large ungreased baking sheet. Using a 1-1/2-inch round cookie cutter, cut out the centers of the remaining 12 squares. Reserve the round cutouts.
Combine the egg and 1 tablespoon water in a small bowl, beat with a fork to blend. Brush the egg wash over the uncut pastry squares on the baking sheet. Place the squares with the centers cut out on top of the uncut squares. Brush the stacked squares with the egg wash.
Combine the melted chocolate and walnuts in a small bowl. Spoon into center holes of the stacked squares. Brush the round cutouts with the remaining egg wash. Place the rounds on top of the filling, pressing down slightly.
Bake in a preheated 400-degree oven until golden brown, about 12-15 minutes. Transfer to a wire rack to cool slightly.