How to Make It
Preheat the oven to 350°. Butter two 9-by-13-inch baking dishes. In a medium bowl, whisk the egg yolks with the eggs, sugar and vanilla seeds. Whisk in the milk, heavy cream and kirsch. Put half the berries in each baking dish and pour the custard over the top. Bake for 20 minutes, or until just set. Remove from the oven and let cool slightly. Dust the tops with confectioners' sugar and serve warm.