Preheat your oven to 180°C (350°F) and line a muffin tin with paper liners, setting it aside.
Gently melt the dark chocolate with the butter in a saucepan over low heat, stirring until smooth and glossy, filling the kitchen with a rich chocolate aroma.
In a large bowl, whisk together the eggs, sugar, and vanilla until the mixture becomes light, fluffy, and slightly pale, about 3-4 minutes.
Pour the melted chocolate and butter into the egg mixture, stirring gently until well combined and smooth.
Sift the flour and salt into the wet mixture, then fold gently with a spatula until just incorporated, ensuring a shiny, smooth batter without overmixing.
Divide the batter evenly among the lined muffin cups, filling each about three-quarters full, and tap the tin lightly on the counter to release any air bubbles.
Bake the cupcakes in the preheated oven for 20-22 minutes, until the tops are just set and a toothpick inserted in the center comes out with moist crumbs.
Remove the cupcakes from the oven, let them cool in the tin for about 10 minutes, then transfer to a wire rack to cool completely.
Once cooled, frost the cupcakes with dark chocolate ganache or your favorite frosting for an extra decadent touch.
Chill the cupcakes in the refrigerator for at least 30 minutes to allow the flavors to meld and the frosting to set before serving.
