Ingredients :

• Dark chocolate (200 g) — Choose one with at least 60-65% cocoa. Below that, the cake will lack depth and be too sweet. A Lindt Excellence 70%, a Nestlé Dessert dark, or whatever you have in stock — the important thing is real dark chocolate, not low-end cooking chocolate that smells like sugar and nothing else.
• Mascarpone (250 g) — This is what does the work. It provides a rich, creamy texture that completely changes the game compared to a classic fondant. No need for a specific brand — generic supermarket mascarpone works great. Just make sure it’s at room temperature before mixing it with the chocolate.
• Eggs (4) — Whole, at room temperature. Take them out of the fridge an hour before if you think of it. Cold eggs can slightly seize the melted chocolate — nothing catastrophic, but the final texture is less smooth.
• Flour (40 g) — Almost nothing. This is intentional: just enough to give a minimal structure without turning it into a classic sponge cake. If you want a gluten-free version, cornstarch works in the same quantity, without changing the taste or texture.