Why It Works
- A small batch of dark-chocolate ganache boosts the flavor and richness of an otherwise traditional American buttercream.
- High-fat Dutch cocoa powder contains more fat and less starch than supermarket brands, for better flavor and richness.
- A small amount of instant espresso adds a subtle bitterness that keeps the sweetness in check, without lending an overt coffee flavor to the frosting.
This recipe combines the speed and ease of an American buttercream with the richness and intensity of ganache, for a bold yet simple chocolate frosting. The exact color and texture will depend on how long the frosting is whipped; stop short for a dark, dense frosting, or continue whipping until it's airy and relatively pale.
In either case, the flavor will depend entirely on the quality of dark chocolate and Dutch cocoa involved, so check out our guides to the best dark-chocolate bars easily found in supermarkets and the best high-fat Dutch cocoa for baking.
- 4 ounces heavy cream (about 1/2 cup; 115g), straight from the fridge
- 4 ounces finely chopped dark chocolate (not chips), around 72% (about 2/3 cup; 115g)
- 12 ounces unsalted butter (3 sticks; 340g), softened to about 65°F (18°C)
- 9 ounces organic powdered sugar (about 2 1/4 cups, spooned; 255g), preferably tapioca-based, such as Wholesome (see note)
- 3 ounces high-fat Dutch cocoa powder (about 1 cup, spooned; 85g)
- 2 teaspoons vanilla extract, plus more to taste
- 3/4 teaspoon (3g) Diamond Crystal kosher salt, plus more to taste; for table salt, use about half as much by volume or the same weight
- 3/4 teaspoon instant espresso powder, plus more to taste
In a small saucepan, bring cream to a simmer. Off heat, add chopped chocolate and whisk until smooth. Set aside and cool to approximately 75°F (24°C). This can be done slowly by letting the mixture cool down over time in the saucepan, or sped up by transferring the ganache to a wide, shallow container to increase its surface area; the faster method will cool the ganache in about 30 minutes.
Place butter in the bowl of a stand mixer, then sift powdered sugar and Dutch cocoa on top to ensure no lumps of either remain in the frosting. Fit stand mixer with a paddle attachment and mix on low until dry ingredients are fully incorporated.
Add vanilla, salt, and espresso powder, then increase speed to medium and beat until frosting is creamy and smooth, pausing along the way to scrape bowl and beater as needed. This will take about 6 minutes, although the exact timing will vary depending on the power of the mixer and the temperature of the ingredients.
Reduce speed to medium-low and add ganache. Once ganache is fully incorporated, pause to scrape bowl and beater with a spatula, then resume mixing a few seconds longer to ensure the frosting is homogeneous. Extending the beating time can create a lighter, paler frosting with a higher yield, while reduced beating can create a denser, darker frosting with a lower yield; which you choose depends on your personal preference. At this stage, the buttercream can be doctored to taste with additional salt, vanilla, or instant espresso powder.
Use buttercream right away or transfer to a large zipper-lock bag, press out air, and seal. The buttercream can be refrigerated for up to 2 weeks or frozen for up to several months. (The main issue with longer storage in the freezer is odor absorption, not spoilage.) Bring buttercream to approximately 72°F (22°C) and re-whip before use; see the troubleshooting guide below for tips on adjusting its consistency.
Troubleshooting: If too cold, the frosting may seem stiff, greasy, or curdled; to fix, melt 1/4 cup frosting until liquid, then return it to the bowl and re-whip. Conversely, if too warm, the frosting may seem soft, loose, or runny; to fix, refrigerate the bowl of frosting for 10 minutes, then re-whip. It can take time to achieve the right temperature and consistency, but it gets easier with practice.
If you don't have organic powdered sugar on hand, conventional powdered sugar will be fine; just add 1/2 teaspoon plain, unsulfured molasses (not blackstrap) along with the salt and vanilla to create a similar depth of flavor. Check out our guide to the differences between conventional and organic powdered sugar for more detail.
Make-Ahead and Storage
In a large zipper-lock bag, the buttercream can be refrigerated for up to 2 weeks or frozen for up to several months.