Preheat Oven:
Preheat oven to 375°F (190°C). Grease an 8-inch round cake pan and line the bottom with parchment paper.
Melt Chocolate and Butter:
In a heatproof bowl, melt chocolate and butter together over a double boiler or in the microwave in 20-second intervals, stirring until smooth.
Mix Sugar and Eggs:
In a separate bowl, whisk together sugar, salt, and eggs until slightly thickened.
Combine Ingredients:
Gradually fold melted chocolate mixture into the egg mixture. Sift cocoa powder over the batter and gently fold until fully combined.
Bake:
Pour batter into prepared pan. Bake for 20–25 minutes, or until the top forms a thin crust and the center is just set. A toothpick inserted in the center should come out with a few moist crumbs.
Cool:
Allow the cake to cool in the pan for 10–15 minutes, then remove and transfer to a wire rack. Cool completely before serving.
Serve:
Dust with powdered sugar or cocoa powder, and serve with fresh berries, whipped cream, or a drizzle of chocolate sauce if desired.