In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer. Do not let it boil.

Remove the saucepan from the heat and add the chopped semi-sweet chocolate. Let it sit for about 2-3 minutes to allow the chocolate to soften.

After the chocolate has softened, whisk the mixture until smooth and fully combined.

Stir in the unsalted butter, vanilla extract, and a pinch of salt. Continue whisking until the butter is melted and the ganache is glossy and smooth.

Allow the ganache to cool at room temperature for about 30 minutes until it thickens slightly. If you want a pourable consistency, use it while still warm; for a thicker spreadable frosting, let it cool longer.

Once the desired consistency is reached, pour the ganache over your prepared cake, allowing it to drip down the sides for a beautiful finish. Alternatively, use a spatula to spread it evenly on top and around the cake.

Let the ganache set for at least 1 hour before serving to ensure it holds its shape.