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A slice of 2 layer white chocolate whisper cake with pistachio frosting and filling, on a white plate beside a cake stand containing the rest of the cake.
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4.75 / 4 votes

White Chocolate Whisper Cake

White chocolate offers the double advantage of velvety, melt-in-the-mouth texture and, because of white cake's gentle flavor, a definite whisper of cocoa butter. This special flavor blends well with a lemon buttercream or, of course, David's pistachio buttercream.
Prep Time30 minutes
Cook Time25 minutes
Total Time55 minutes
Course: Dessert
Cuisine: American
Servings: 12 servings
Calories: 479

Ingredients

  • Nonstick baking spray
  • cake flour, for the pans
  • 6 ounces white chocolate
  • 4 1/2 large (4.75 oz) egg whites, room temperature
  • 1 cup whole milk, room temperature
  • 1 1/2 teaspoons vanilla extract
  • 3 cups (10.5 oz) sifted cake flour
  • 1 cup plus 3 tablespoons (8.5 oz) granulated sugar
  • 1 tablespoon plus 1 1/2 teaspoons baking powder
  • 3/4 teaspoon salt
  • 9 tablespoons (4.5 oz) unsalted butter, softened to room temperature
  • 3 tablespoons neutral oil
  • David's Pistachio Buttercream Frosting
  • Chopped pistachios, for decorating (optional)
US - Metric

Instructions

  • Preheat the oven to 350°F (177°C). Coat two (9-inch | 23-cm) cake pans with baking spray, line with parchment, spray again with cooking spray, then lightly flour.
    A person lining two cake pans with parchment paper rounds.
  • In a double boiler over hot (not simmering) water, melt the chocolate, stirring frequently. Remove from the water.
    White chocolate melted over a double boiler.
  • In a medium bowl, lightly combine the egg whites, 1/4 cup (61 g) of the milk, and the vanilla.
    A person whisking egg whites and vanilla in a glass bowl.
  • In the bowl of a stand mixer fitted with the paddle attachment or in a large mixing bowl using a hand mixer, combine the dry ingredients and mix on low speed for 30 seconds to blend. Add the butter, oil, and the remaining 3/4 cup (181 g) milk.
    Butter, flour, oil, and milk in a glass mixing bowl.
  • Mix on low speed until the dry ingredients are moistened. Increase to medium speed (high speed if using a hand mixer) and beat for 1 1/2 minutes to aerate and develop the cake's structure. Scrape down the sides. Gradually add the egg mixture in 3 batches, beating for 20 seconds after each addition to incorporate the ingredients and strengthen the structure. Scrape down the sides.
    Beaten cake batter in a glass mixing bowl.
  • Add the melted chocolate and beat to incorporate.
    Melted white chocolate being folded into batter in a glass mixing bowl.
  • Divvy the batter evenly between the prepared pans and smooth the surface with a spatula.

    ☞ TESTER TIP: Use a scale to divide the batter exactly between the two cake pans. It's about 600 grams per pan.

    Cake batter being poured into a cake pan.
  • Bake until a tester inserted near the center comes out clean and the cake springs back when pressed lightly in the center, about 25 minutes. The cakes should start to shrink from the sides of the pans only after removal from the oven.

    ☞ TESTER TIP: If the cakes are becoming too dark during baking, cover with foil for the final few minutes of baking.

    Two baked cakes on a wire cooling rack.
  • Let the cakes cool in the pans on racks for 10 minutes. Spray the cooling racks with baking spray. Loosen the sides with a small metal spatula and invert onto the greased wire racks. To prevent splitting, reinvert so that the tops are up and cool completely.
    A person removing parchment from a baked cake layer.
  • If serving immediately, frost with David's pistachio buttercream frosting.
  • If serving later, wrap tightly with plastic wrap and store at room temperature for up to 2 days, in the refrigerator for up to 5 days, or in the freezer for up to 2 months. Frost with pistachio buttercream before serving.
  • To frost the cakes, place one cake on a serving platter. Use an offset spatula to spread the pistachio buttercream frosting in an even layer over the top. Top with the second cake. Spread frosting generously over the top and sides. Top with fresh berries or pistachios, if using.
    Two cake layers stacked on top of each other being topped with buttercream frosting.

Notes

  1. Don't rush the melting--Be cautious when melting the white chocolate, and don't try to rush the process, as it can seize quickly.
  2. Make-ahead & storage--You can make the cake layers up to 5 days ahead of time and then frost them the day you serve. Store the cake layers, wrapped in plastic, at room temperature for up to 2 days or in the fridge for up to 5 days.
  3. Use cake strips--Whenever I bake cakes, I use cake strips. You wet them and wrap them around the outside of the cake pan. It prevents the cake from doming.

Nutrition

Serving: 1portion, cake only | Calories: 479kcal | Carbohydrates: 69g | Protein: 9g | Fat: 19g | Saturated Fat: 12g | Monounsaturated Fat: 4g | Trans Fat: 1g | Cholesterol: 29mg | Sodium: 171mg | Fiber: 1g | Sugar: 26g