Gather all your ingredients and have them measured out and ready to go. This will make the cooking process smooth and enjoyable.
In a medium saucepan over low heat, combine the chopped bittersweet chocolate and one tablespoon of butter. Stir frequently until the chocolate is melted and smooth. If you prefer, you can use a double boiler for this step.
Once the chocolate is melted, add the granulated sugar and unsweetened cocoa powder to the saucepan. Stir well to combine, ensuring there are no lumps.
Gradually pour in the heavy whipping cream while continuously stirring. The mixture will thicken as you blend in the cream, creating a beautiful sauce.
Remove the saucepan from the heat and add the remaining pieces of butter and the vanilla extract. Stir until the butter is completely melted and combined, resulting in a rich, glossy sauce.
Let the chocolate sauce cool slightly before serving. It can be drizzled warm over desserts or stored for later use.
