Makes about 5 cups, or enough to fill and ice an 8- or 9-inch cake
- 1 1/2 cups unsweetened cocoa powder
- 1/2 cup (1 stick) unsalted butter, at room temperature
- 1/2 cup light corn syrup
- 1 teaspoon vanilla extract
- 1/2 teaspoon kosher salt
- 1/2 cup hot water
- 2 1/4 cups confectioners’ sugar, sifted
- In a stand mixer fitted with the paddle attachment, cream together the cocoa powder and butter on low speed until blended, scraping down the bowl with a rubber spatula as needed, until very smooth, about 2 minutes. Add the corn syrup, vanilla extract, and salt and continue to mix until evenly blended, 1–2 minutes. Add the hot water and mix on low speed until evenly blended.
- Add the confectioners’ sugar, mix on low speed until blended, then increase the speed to medium and whip until the icing is very smooth and light, 2–3 minutes.
- Use immediately or transfer to a storage container, cover tightly, and refrigerate for up to 1 week. Allow the icing to return to room temperature before using it. If necessary, beat the icing using the paddle attachment on low speed until it is smooth and spreadable.