Rinse and dry strawberries, hull and cut into bite-size pieces. Clean raspberries. Combine both types of berries.
Beat cream with powdered sugar until stiff. Arrange 3 ladyfingers side by side on a plate, top with cream. Arrange 1/4 of berries on cream, spread cream on top of berries and top with 3 more ladyfingers. Prepare other pastries in the same manner. Dust with powdered sugar and serve garnished with mint leaves.