Mix strawberries, blackberries, 1/3 cup sugar, and orange juice together in a bowl. Cover the bowl with plastic wrap and refrigerate, 2 hours to overnight.
Stir mascarpone cheese, lemon zest, 1/2 teaspoon sugar, and vanilla extract together in a bowl.
Spread mascarpone mixture over the top of each shortcake half; sprinkle about 1 teaspoon sugar over the top to cover. Caramelize the sugar using a kitchen torch, 20 to 30 seconds per shortcake. Place each shortcake in a shallow bowl and surround with berries and accumulated juices.
