I used to call this “pudding buttercream” before I knew it’s true name: ermine. This technique involves preparing a simple pudding-style custard base, then whipping butter into it to create the final frosting. This method has become one of my go-tos, because it allows for a really creamy frosting that’s thick and pipable, but also not too sweet. Be sure to let the pudding base cool to room temperature before whipping in the butter, but don’t be tempted to refrigerate it to speed it up. If it gets even a bit cold, it will make the frosting likely to split. If you’re in a hurry, pour the pudding onto a baking sheet—the greater surface area will allow it to cool much faster. —Erin Jeanne McDowell
Test Kitchen Notes
Bake It Up a Notch is a column by Resident Baking BFF Erin Jeanne McDowell. Each month, she'll help take our baking game to the next level, teaching us all the need-to-know tips and techniques and showing us all the mistakes we might make along the way. Today, a very sweet lesson in all things frostings, icings, and glazes. —The Editors
- Prep time 5 minutes
- Cook time 5 minutes
- makes 4 cups (enough to fill and frost one 8- or 9-inch cake (up to 3 layers) or 24 cupcakes
1 3/4 cups
(398 grams) granulated sugar
(90 grams) all purpose flour
(28 grams) unsweetened cocoa powder
(5 grams) instant espresso powder (optional)
(2 grams) fine sea salt
(460 grams) whole milk
(454 grams) unsalted butter, at room temperature
(15 grams) vanilla extract
- In a medium pot, whisk the granulated sugar, flour, cocoa powder, espresso powder (if using), and salt. Whisk in the milk.
- Begin to heat the mixture over medium heat, whisking constantly, until the mixture thickens and becomes pudding like, 2 to 3 minutes. Transfer to a heat-safe storage container, cover directly with plastic wrap, and let cool to room temperature.
- Place the butter in the bowl of an electric stand mixer fitted with the whisk attachment. Whip on medium-high speed until the mixture is light and fluffy, 2 to 3 minutes. With the mixer running, add the room temperature pudding mixture 1 heaping tablespoon (about 25 grams) at a time, mixing until each is fully incorporated before adding the next.
- Once all of the pudding base is incorporated, add the vanilla extract and mix to combine.