Place each waffle cone in a tall cup or bowl. Scoop ice cream into cones. Top with ice cream topping or Berry Sauce.
Add berries to top of sundae. Sprinkle with mint leaves. Makes 4 sundaes.
In a medium saucepan stir together frozen unsweetened raspberries, blackberries, blueberries, and sugar over medium heat. Bring to boiling. Reduce heat. Simmer, uncovered, until thickened, about 15 minutes. Remove from heat; cool slightly. Place berry mixture in blender and cover; blend or process until smooth. Store leftover sauce, tightly covered, up to two weeks in refrigerator. Makes 2 cups.