Preheat oven to 350 degrees F.

To make Peach Filling: Heat frozen juice concentrate in a stovetop- and oven-safe 2-quart casserole over medium heat for 3 minutes. Add peaches, and reduce heat to low. Cook for 5 minutes, or until peaches soften. Add sugar, and stir to mix. Add peach brandy, and cook for 3 minutes, or until liquid has consistency of syrup. Turn off heat, and remove 11/2 cups of syrup, setting it aside in a small saucepan. Dissolve cornstarch in water, and stir into peaches.

To make Cinnamon-Walnut Topping: Put flour, wheat germ, sugar, walnuts and cinnamon into a food processor, and pulse to mix. Add prune puree, and process until mixture has the consistency of a moist crumb. Sprinkle generously over filling.

Bake for 30 minutes, or until lightly browned. Bring reserved syrup to a boil over medium heat, stirring frequently. Cook down, and reduce syrup to about 1 cup. Spoon syrup over warm crisp, and serve.