3tablespoonmilkcan add in another tablespoon if needed
Melt the semi-sweet chocolate and set aside to cool a bit.
If you're using a stand mixer, use the paddle attachment. If you don't have a paddle attachment, just use your whisk attachment. If you don't have a stand mixer, that's okay. A hand-mixer will work just fine. Cream the butter at medium speed until it's smooth.
Add in the cocoa powder and beat on low until combined, then on medium until well incorporated. Scrape down the sides of the bowl and mix again.
Add in 3 cups of powdered sugar. Beat on low until combined, then on medium until fully incorporated.
Add 2 tablespoons of milk plus the last 3 cups of powdered sugar. Beat on low until combined, then on medium until fully incorporated. Scrape down the sides of the bowl, then mix again. (If it's too thick at this point, add another tablespoon or two of milk and mix.)
Add vanilla paste, or extract and the cooled down melted chocolate. Beat until well combined.
Check the texture of your buttercream and if it's still too thick, add milk only a tablespoon at a time, and mix after each addition.
It's okay to leave this buttercream out of the fridge for a couple days (as long as the room is fairly cool). After that, it should be refrigerated. This buttercream can stay in the fridge for about a week.Nutritional values are an estimate. Make sure to check out the TIPS & FAQs for this recipe in the blog post, which may answer questions about substitutions.This recipe card may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases.