Place your chocolate in a microwave-safe bowl and microwave for 30 seconds. Stir well. Return chocolate to microwave and heat for another 15 seconds and stir again. Continue heating chocolate for 15 seconds, stirring after each, until chocolate is completely melted and smooth.
Allow chocolate to cool for at least 10-15 minutes, stirring occasionally. You want chocolate to cool so that it is not hot to the touch, otherwise it will melt your butter and sugar and the frosting will not turn out.
While the chocolate is cooling, place butter in a separate bowl and use a stand mixer or electric mixer to beat until creamy.
Add melted, cooled chocolate and stir well.
Gradually add sugar, scraping down the sides and bottom of bowl occasionally so that ingredients are well combined.
Sprinkle in salt and vanilla extract, stir well.
With mixer on low, gradually add heavy cream to frosting. Gradually increase speed to high and beat for 30 seconds.
Pipe or spread frosting onto prepared, cooled baked good.
¹How many cupcakes/how much cake will this frost?
This recipe will modestly cover 24 cupcakes or generously (as seen in the photos above) cover 12 cupcakes. You can also cover an 8" or 9" cake or a 9x13" sheet cake. If you want to use the frosting for decorative borders around the cake, increase the recipe by 50%.
If you don't have semisweet chocolate bars you can use 1 cup (170g) of semisweet chocolate chips instead.
I recommend using unsalted butter, but if you only have salted on hand you can use that, just leave out the salt in this recipe.
Making in Advance
This frosting may be made in advance. Store in an airtight container in the refrigerator with a piece of plastic wrap pressed firmly against the surface. When ready to use, let it come to room temperature then remove the plastic wrap and stir again to regain that smooth consistency before using.
I used an Ateco 848 piping tip to pipe the cupcakes seen in the photos above.