Black-and-White Chocolate Marble Pound Cake with Vanilla Bean and Black Cocoa Glazes
 
Makes 1 (10-inch) Bundt Cake
Ingredients
  • 2 cups (454 grams) unsalted butter, room temperature and divided
  • 3 cups (600 grams) granulated sugar, divided
  • 3 teaspoons (12 grams) vanilla extract,divided
  • 4 large egg whites (120 grams),room temperature
  • 4 ounces (115 grams) white chocolate, melted
  • 2 ¼ cups (281 grams) cake flour, divided
  • 2 teaspoons (6 grams) kosher salt, divided
  • 2 large eggs (100 grams), room temperature
  • 4 large egg yolks (74 grams), room temperature
  • ¾ cup (64 grams) black (Dutch process) cocoa powder*, sifted
  • ½ cup (120 grams) whole buttermilk, room temperature
  • Vanilla Bean Glaze (recipe follows)
  • Black Cocoa Glaze (recipe follows)
Instructions
  1. Butter and flour a 10-inch Bundt pan.
  2. In the bowl of a stand mixer fitted with the paddle attachment, beat 1 cup (227 grams) butter, 11⁄2 cups (300 grams) sugar, and 1 ½ teaspoons (6 grams) vanilla at medium speed until flu y and pale, at least 6 minutes. Add egg whites, one at a time, beating well after each addition, about 15 seconds. Scrape bottom and sides of bowl with a rubber spatula. With mixer on medium-high speed, add melted white chocolate, beating until smooth, about 1 minute. Add 1 ½ cups (187 grams) flour and 1 teaspoon (3 grams) salt, and stir with a rubber spatula just until combined. Scrape white batter into a bowl, and set aside.
  3. Return bowl to stand mixer. With the paddle attachment, beat remaining 1 cup (227 grams) butter, remaining 1 ½ cups (300 grams) sugar, and remaining 1 ½ teaspoons (6 grams) vanilla at medium speed until fluffy and pale, at least 6 minutes. Add eggs, one at a time, beating well after each addition, about 15 seconds. Add egg yolks, two at a time, beating well after each addition, about 15 seconds. Scrape bottom and sides of bowl with a rubber spatula. With mixer on medium-high speed, beat until smooth, about 1 minute. Add cocoa, remaining ¾ cup (94 grams) flour, and remaining 1 teaspoon (3 grams) salt. With mixer on low speed, add buttermilk, beating just until batter comes together. Scrape bottom and sides of bowl with a rubber spatula, and stir just until combined.
  4. Using a large (2- to 3-ounce) spring-loaded ice cream scoop, alternately scoop white and black batters into prepared pan. Tap pan lightly on counter to settle batter.
  5. Place pan in a cold oven, and bake at 300°F (150°C) until lightly browned on top and a wooden pick inserted near center comes out clean, 1 ½ to 2 hours. (This bake time depends on how long it takes your oven to preheat. Start checking after 1 ½ hours, and continue baking in 10-minute intervals until cake is done.) Let cool in pan on a wire rack for 10 minutes. Invert cake onto wire rack, and unmold from pan. Let cool completely.
  6. Alternately spoon Vanilla Bean Glaze and Black Cocoa Glaze onto cake, letting each one drip down grooves of cake. Alternatively, pour Black Cocoa Glaze over cake, and let stand until hardened, about 10 minutes. Pour Vanilla Bean Glaze over top, and let stand until hardened, about 10 minutes.
Notes
*Black cocoa is available online or in specialty food stores. We used King Arthur Flour Black Cocoa, but any brand will work. Black cocoa is a deeper color than regular cocoa and further alkalized—or “Dutch processed”—to remove virtually all acidity. To make sure it doesn’t dry out the cake batter, this recipe has extra buttermilk to provide more moisture and acidity.
Recipe by Bake from Scratch at https://staging.bakefromscratch.com/black-white-chocolate-marble-pound-cake-vanilla-bean-black-cocoa-glazes/