Make 8 sandwiches, using 2 slices of pound cake and 1/4 cup softened mango sorbet each. Wrap each sandwich tightly with plastic wrap, and freeze for 2 hours.
Dissolve sweetener in lime juice and coconut milk; toss with blueberries, mango, strawberries, and peach slices.
To serve, unwrap the sandwiches and place each onto a dessert plate. Top with a mound of fruit and garnish with whipped cream and a mint sprig.
