In a medium bowl, combine 1/3 cup sugar, orange zest, and orange juice. Gently toss in the fresh raspberries, blackberries, blueberries, and sliced strawberries until coated. Cover and refrigerate for about 45 minutes to allow juices to release.

In a chilled mixing bowl, pour in the heavy whipping cream and beat with an electric mixer on medium-high speed until soft peaks begin to form, typically taking about 2-3 minutes.

In a large bowl, whisk together mascarpone cheese, remaining sugar, and vanilla extract until smooth. Gently fold in the whipped cream using a spatula.

Reserve the juices from the berries and dip the ladyfinger cookies quickly into the juices. Layer the cookies in a 13x9-inch dish, followed by half of the berry mixture and a layer of the mascarpone mixture. Repeat the layers.

Cover the dish tightly and refrigerate the assembled Berry Tiramisu overnight, or for at least 6 hours.

When ready to serve, remove from the refrigerator and top with additional fresh berries and a sprinkle of orange zest. Cut into squares using a serrated knife dipped in warm water.