Ecclefechan Tart

Name: Ecclefechan Tart
Ingredients: 1 cup all purpose flour; 3/4 cup powdered sugar; Pinch of salt; 6 tablespoons (3/4 stick) chilled unsalted butter, cut into 1/2-inch cubes; 4 teaspoons chilled whipping cream; 1/2 cup (1 stick) unsalted butter, melted; 1/2 cup (packed) dark brown sugar; 2 large eggs; 1 tablespoon fresh lemon juice; 1 teaspoon (packed) grated lemon peel; 1/2 teaspoon ground cinnamon; 2 cups dark raisins; 1 cup walnuts, coarsely chopped; 1 3/4 cups chilled whipping cream; Toasted walnuts