Place the dough in a large bowl, cover with plastic wrap and leave at room temperature for 45 minutes. Preheat the oven to 230°C (450°F).
For the berry topping: In a saucepan, combine the sugar and cornstarch, then add the chilled apple juice and 125 ml (1/2 cup) of berries. Cook over medium-high heat until the mixture thickens. Remove from heat, add the remaining berries and stir to combine. Set aside at room temperature.
Sprinkle the back of a baking sheet with cornmeal and place the dough on top. Dip your fingertips in melted butter and press the dough out, gently but firmly, into a 25 cm (10 in) circle. Brush the dough with the remaining melted butter and slide it carefully onto a pizza pan. Dot the pizza with spoonfuls of Ricotta and marmalade and arrange the Mozzarella Fresca cheese slices over the top. Sprinkle with sugar crystals.
Bake for about 15 minutes or until the crust is puffed and golden on the edges. Garnish with the warm berry mixture and dust with icing sugar.
