Thaw harvest apples in microwave at MEDIUM (50% power) 5 to 6 minutes; set aside.
Combine apples, cinnamon, and lemon juice in a medium bowl; stir well, and set aside. Combine marshmallow creme and cream cheese in a small bowl beating at medium speed with an electric mixer until blended. Fold into apple mixture. Spoon into pastry shell.
Combine brown sugar and flour in a small bowl; cut in butter until mixture resembles coarse meal. Stir in walnuts. Sprinkle over apple mixture. Bake at 375° F for 30 to 40 minutes.
Combine confectioner's sugar, water, and vanilla in a small bowl; stir well. Drizzle over warm pie. Serve at room temperature or chilled.Servings: 1 - 9 inch pie