01 -
Preheat the oven to 200ºC. Generously butter a 1.75L baking or gratin dish. Arrange the sliced plums evenly across the bottom of the dish.
02 -
In a medium bowl, whisk together the eggs, flour, sugar, heavy cream, salt, and about one-third of the milk until completely smooth with no lumps. Gradually whisk in the remaining milk, kirsch, and vanilla extract until well combined.
03 -
Pour the custard mixture over the plums in the baking dish. Bake on the middle rack until the custard is just barely set in the center, approximately 20 minutes.
04 -
Remove from the oven and place on a cooling rack. After one minute, sprinkle the reserved teaspoon of sugar over the top for a delicate finish.