Preheat and prepare the dish

• Preheat the oven to 325 °F (165 °C).
• Lightly butter a 2-quart oval baking dish.

Melt the butter

• Melt the butter and set it aside to cool.

Whip eggs and sugar

• In the bowl of an electric mixer fitted with the paddle attachment, beat the eggs and sugar on medium-high speed until very thick and light yellow.

Sift the dry ingredients

• Meanwhile, sift the cocoa powder and flour together and set aside.

Combine the batter

• Reduce the mixer speed to low and add the vanilla seeds, the framboise if using, and the cocoa and flour mixture; mix only until combined.
• With the mixer still on low, slowly pour in the cooled butter and mix just until combined.

Bake in a water bath

• Pour the batter into the prepared dish and place it in a larger baking pan.
• Add enough of the hottest tap water to the pan to come halfway up the side of the dish.
• Bake for exactly 1 hour; a cake tester inserted 2 inches from the side will come out mostly clean, while the center stays very under-baked.

Cool and serve

• Allow to cool, then serve with vanilla ice cream.