This chocolate frosting is an easy recipe that comes together in 20 minutes and tastes like chocolate ice cream! It's based on my easy mock-Swiss meringue vanilla buttercream and is perfect for frosting wedding cakes, filling birthday cakes, using under fondant, and swirling on cupcakes.
Place the pasteurized egg whites, powdered sugar, and cocoa powder into the bowl of your stand mixer with the whisk attachment and mix on high for 1 to 2 minutes to dissolve the sugar.
Add the vanilla, salt, and softened butter in small chunks and whip on high until light and fluffy, about 8-10 minutes. Once it no longer tastes like butter, it’s done.
If your buttercream looks curdled, remove about 1 cup of buttercream and melt it in the microwave for 10-15 seconds until it is barely melted. Pour it back into the whipping buttercream to bring it all together and make extra creamy frosting.
Switch to the paddle attachment and mix on low speed for about 10 minutes to remove the air bubbles and create very smooth buttercream. This is optional but will make it extra creamy. This buttercream can be left at room temperature for 24 hours, refrigerated for up to two weeks, or frozen up to 6 months.
You MUST use pasteurized egg whites for this recipe, if you don't have pasteurized egg whites then you can use my chocolate Swiss-meringue recipe instead. Pasteurized egg whites are heat-treated (like milk) so they are safe to eat, raw egg whites are not. You can also pasteurize your own egg whites.
You can also use a large bowl and mix with an electric mixer by hand, just mix for longer to get the right consistency.
After refrigerating or freezing, always re-whip your buttercream before use. I melt one cup of the buttercream and mix it back in while whipping on high to make it creamy again.
Instead of using cocoa powder, you can melt down about 4 ounces of real chocolate, cool it to about 80°F, and add it to your finished buttercream.
If you want a more rich chocolate flavor, you can add more cocoa powder! You can also increase the powdered sugar for a sweeter frosting, but I wouldn't recommend adding less sugar.