Vanilla Bean German Buttercream
 
Ingredients
  • 1⅔ cups (333 grams) granulated sugar
  • 4 tablespoons plus 1 teaspoon (35 grams) cornstarch
  • 3 large eggs (150 grams), room temperature
  • 3 large egg yolks (56 grams), room temperature
  • 1 teaspoon (3 grams) kosher salt
  • 2¼ cups plus 2 tablespoons (570 grams) whole milk
  • 3 teaspoons (18 grams) vanilla bean paste (see Note)
  • 4½ cups (1,021 grams) unsalted butter, cubed and softened
Instructions
  1. In a medium bowl, whisk together sugar and cornstarch. Add eggs, egg yolks, and salt, whisking to combine.
  2. In a medium saucepan, heat milk and vanilla bean paste over low heat just until bubbles form around edges of pan. (Do not boil.) Pour half of hot milk mixture into sugar mixture, whisking constantly. Whisk until well combined; return mixture to saucepan, and heat over medium heat, whisking constantly, until it begins to bubble. It will thicken quickly. Once it has thickened, cook for 1 minute. Pour into a shallow container or the bowl of a stand mixer, and cover with a piece of plastic wrap, pressing wrap directly onto surface of pastry cream to prevent a skin from forming. Refrigerate for at least 4 hours or preferably overnight. (If you need to speed this process up, place pastry cream in a bowl, and place bowl in an ice bath. Stir frequently.)
  3. In the bowl of a stand mixer fitted with the whisk attachment, beat pastry cream at medium speed until creamy and smooth. Add butter, a few cubes at a time, beating until well combined after each addition. (Mixture may look curdled at some point, but it will come together.) Switch to the paddle attachment, and beat at low speed for 2 to 3 minutes to help release any air bubbles. Store in an airtight container until ready to use. If refrigerating, let stand at room temperature to warm slightly, and rewhip until smooth before using.
Notes
The vanilla flavor in this buttercream comes from vanilla bean paste, which also gives the buttercream little black flecks of vanilla bean seeds. Vanilla extract will work well, too.
Recipe by Bake from Scratch at https://www.bakefromscratch.com/earl-grey-layer-cake-vanilla-bean-german-buttercream/