Decadent Trifle 8 oz. 70-percent dark chocolate, finely chopped 4 tbsp. unsalted butter, cubed 8 oz. white chocolate, finely chopped 2 tbsp. plus 1 tsp. sweet olorosso sherry 1 cup seedless raspberry jam Make the dark chocolate custard: Whisk together 1⁄ 2 cup sugar, 2 tbsp. cornstarch, and 1⁄ 4 tsp.