How to Make It
In a small, heavy saucepan, combine the Riesling with 1/2 cup of the sugar and the vanilla bean and seeds. Bring to a boil over high heat, stirring, until the sugar dissolves. Continue to boil, undisturbed, until reduced to 1/2 cup, about 8 minutes. Let cool slightly.
Put the strawberries in a bowl and strain the syrup over them. Save the vanilla bean for another use.
In a medium bowl, using an electric mixer, whip the mascarpone with the cream and the remaining 1 tablespoon of sugar until soft peaks form. Place 2 cake triangles in each of 6 dessert bowls and top with half of the strawberries. Repeat with the remaining cake and strawberries. Spoon any remaining syrup over each bowl, dollop on the mascarpone cream and serve.