Combine the whipping cream and chocolate in a small microwavable bowl. Heat on High for 30 seconds; stir until the chocolate is melted. Cover and refrigerate at least 1 hour or until completely chilled (or place in the freezer for 15 minutes).
Mix the strawberries and sugar in a medium bowl; set aside.
Beat the whipping cream mixture until stiff peaks form. Fold in the sour cream. Spoon 1/4 cup berries into 4 dessert dishes.
Top each evenly with the sour cream mixture. Top each dish with the remaining strawberries. Garnish with mint sprigs, if desired.