Preheat the oven to 180°C (approximately 350°F). Line the bottom of a 26 cm (approximately 10-inch) springform pan with parchment paper.
In a food processor, process the chocolate wafers to fine crumbs. Add the melted butter and pulse until combined. Press into the bottom of the pan.
Drain the cherries in a colander.
Separate the eggs. In the bowl of an electric mixer, beat the egg whites until stiff, sprinkle 2 tablespoons of sugar over the egg whites and beat until stiff and shiny. In another bowl, beat the egg yolks with cream cheese, quark, cornstarch, remaining sugar, vanilla sugar, orange zest and juice until smooth. Fold in the egg whites.
Scrape into the springform pan, scatter the well-drained cherries over and bake until golden brown and set, 50-60 minutes. If the cake is getting too dark, tent with foil. Remove from oven and cool in the pan. Unmold and serve dusted with powdered sugar.