Using 1 1/4-inch ice-cream scoops (or melon ballers) gives this sundae it's whimsical, delicate appearance.
Line two small baking pans with parchment paper. Using a miniature ice-cream scoop, place scoops of ice cream on prepared pan; transfer to freezer. Repeat process with sorbet. Let scoops freeze 30 minutes.
Arrange scoops of ice cream and sorbet among four dishes; top with raspberry sauce, marshmallow sauce, and raspberries. Serve.