Chocolate Pavlova with Chocolate Mascarpone Mousse and Fresh Berries

Name: Chocolate Pavlova with Chocolate Mascarpone Mousse and Fresh Berries
Ingredients: 3 large egg whites at room temperature; 1/4 teaspoon cream of tartar; pinch of coarse sea salt; 1/2 cup plus 1 tablespoon (100 g) superfine (baker’s) white sugar; 1/4 cup (30 g) confectioner’s (powdered) sugar; 1/3 cup (35 g) unsweetened cocoa powder; 1 1/2 cups heavy whipping cream; 9 oz of dark chocolate, chopped; 1 2/3 cups mascarpone; pinch of nutmeg; 2 tablespoon Cointreau or Grand Marnier or other orange liqueur (or orange juice if you prefer); 1/2 cup of mascarpone cheese; 2 tablespoon of confectioner’s (powdered) sugar; 1 cup heavy cream