Preheat the oven to 180°C (350°F). Grease 4–6 small bundt molds or ramekins and set them on a tray.

Melt the dark chocolate and butter together over a gentle bain-marie or in short bursts in the microwave, stirring until smooth. Allow the mixture to cool just enough that it is warm, not hot.

In a bowl, whisk the granulated sugar and eggs until light and slightly airy; fold in the teaspoon of vanilla.

Fold the melted chocolate into the egg mixture with a soft touch. Gently fold in the flour and salt until just combined — the batter should hold a glossy, dense ribbon.

In a separate bowl, beat the cream cheese with powdered sugar and vanilla until smooth.

Fold in the whipped cream to keep the mixture light, then stir in the chocolate chunks.

Fill each mold halfway with the chocolate batter.

Spoon a generous dollop of the cheesecake filling into the center, leaving room at the top.

Cover with the remaining chocolate batter, sealing the edges so the cheesecake remains tucked inside.

Bake for 12–15 minutes. The edges should be set and spring back lightly while the center remains soft and slightly trembling.

Do not overbake — the contrast between set shell and molten heart is everything.

For the ganache, heat 1/2 cup heavy cream until steaming (do not boil) and pour over the semi-sweet chocolate chips.

Stir until glossy and smooth.

Let the cakes cool in their molds for 5 minutes, then invert carefully onto plates.

Pour warm ganache generously over each cake so it lands in luminous ribbons. Serve immediately while the center is molten.