Prepare and bake cake according to package directions for a 10-in. tube pan. Drain the berries, reserving juice in a 2-cup measuring cup; add enough water to the juice to measure 1-1/4 cups. Set berries aside.
Pour juice mixture into a microwave-safe bowl; cover and microwave on high for 3-4 minutes or until mixture comes to a boil. Stir in gelatin until dissolved. Stir in the ice cream until melted. Fold in the berries. Refrigerate for 30 minutes or until set but not firm.
For frosting, in a large bowl, beat cream until thickened. Gradually add applesauce; beat until stiff peaks form. Set aside. Cut a 1-in. slice off the top of cake; set aside.
Using a sharp knife, cut a tunnel out of the cake, leaving a 1-in. wall on all sides; carefully remove cake from inside and save for another use. Fill tunnel with berry mixture; replace cake top. Spread frosting over top and sides of cake. Store in the refrigerator Yield: 12-16 servings.