Ingredients :
CAKE
3 large eggs, separated and room temperature
1¾ cups granulated sugar, divided
1 cup unsalted butter, softened
3 cups cake flour
½ teaspoon baking soda
¼ teaspoon kosher salt
1 cup whole buttermilk, room temperature
1 cup seedless blackberry jam
BROWN SUGAR BUTTERCREAM
2 cups firmly packed light brown sugar
1 cup heavy whipping cream
⅓ cup unsalted butter, cubed
1 teaspoon vanilla extract
¼ teaspoon kosher salt
4⅔ cups confectioners’ sugar, sifted
¼ cup chopped walnuts
¼ cup chopped dried cherries
¼ cup chopped dried dates
Garnish: fresh blackberries, fresh mint sprigs
Directions :
- Preheat the oven to 350 degrees. 3 (8-inch) round cake pans should be floured-sprayed with baking spray. Pan bottoms should be lined with parchment paper and coated with flour-based baking spray.
- Whip egg whites for about a minute at medium-low speed in a stand mixer bowl equipped with the whisk attachment. Add 1/4 cup of granulated sugar in a slow, steady stream while the mixer is running. Beat for three to four minutes, increasing the tempo to medium-high. In a medium dish, combine the egg whites; put aside.
- Transfer the bowl back to the mixer and add the paddle attachment. Beat the butter and remaining 112 cups of granulated sugar for 3 to 4 minutes at medium speed, scraping down the sides of the bowl halfway through. One at a time, beat thoroughly after each addition of egg yolks.
- Combine the flour, salt, and baking soda in a medium basin. Buttermilk and jam are whisked together in a medium dish. With the mixer running on low speed, gently add the flour mixture to the butter mixture in pairs, beginning and finishing with the flour mixture. Beat each addition just until incorporated. Just until mixed, fold one-third of the beaten egg whites into the batter. Just until incorporated, fold in the remaining egg whites. Pour batter into prepared pans and smooth tops with an offset spatula.
- Bake for 25 to 30 minutes, or until golden brown on top and a wooden pick inserted in the center comes out clean. Allow pans to cool for 10 minutes. Take out of pans and let wire racks serve as final cooling surfaces.
- To make the buttercream, mix the brown sugar, cream, and butter in a 3-quart pot. Cook, stirring regularly, over low heat until the butter is melted. Without stirring, turn the heat up to medium and cook the mixture for 5 to 7 minutes, or until it turns amber in color. Add salt and vanilla and stir. Allow to cool for an hour to an hour and a half.
- Beat the cooled brown sugar mixture for two minutes at medium speed in the bowl of a stand mixer with the paddle attachment. 2 cups of confectioners’ sugar should be added while the mixer is on low, and it should be mixed well while scraping the bowl’s edges as necessary. Add the remaining confectioners’ sugar and beat for a further two minutes at medium speed.
- Combine 1 cup buttercream, walnuts, cherries, and dates in a small bowl by stirring the ingredients just until mixed.
- Stack the cake layers, sandwiching each one with 12 cup buttercream and the walnut mixture. Spread the leftover buttercream on the cake’s top and sides. If desired, add mint and blackberries as a garnish.