In medium saucepan, combine prunes, peaches, raisins and water; mix well. Bring to a boil. Reduce heat; simmer 10 minutes. Drain if necessary. Stir in 1/4 cup sugar, cinnamon and walnuts. Cool 20 minutes.
Meanwhile, let both crust pouches stand at room temperature for 20 minutes.
Heat oven to 375°F. Remove crusts from pouches. Unfold crusts; remove plastic sheets. Place on ungreased large cookie sheet; press out fold lines.
For each foldover, spoon fruit mixture onto half of crust to within 1/2 inch of edge. Fold remaining half of crust over filling; press edge firmly to seal. Flute edge; cut slits in top crust. Brush each foldover with water; sprinkle with 1 teaspoon sugar.
Bake at 375°F. for 27 to 31 minutes or until crust edges are golden brown. Serve warm or cool.