Alabama Lane Cake
For the cake:
1 cup (2 sticks) unsalted butter, at room temperature, plus more for pans
2 cups sugar
1 teaspoon pure vanilla extract
3¾ cups sifted cake flour (not self-rising), plus more for pans
3½ teaspoons baking powder
¾ teaspoon kosher salt
1 cup milk
8 large egg whites
For the glaze:
8 large egg yolks
4 whole large eggs
1½ cups sugar
2½ cups (5 sticks) unsalted butter, cut into pieces, at room temperature (For ease of handling, cut into pieces while butter is cold, then allow pieces to come to room temperature.)
¼ cup bourbon
For the filling:
2 cups raisins, preferably large, such as muscat or monukka, finely chopped
½ cup bourbon
2 ¾ cups shredded unsweetened coconut
1¼ cups chopped pecans
½ cup candied kumquats, drained and chopped
Preheat oven to 375°F. Butter and flour 4 round 9-inch cake pans; set aside.
In the bowl of an electric mixer fitted with the paddle attachment, cream butter, sugar and vanilla until light and fluffy. Whisk together flour, baking powder and salt. Alternating with the milk, add these whisked dry ingredients to butter mixture in 3 additions to make batter. Begin and end with the dry ingredients.
In a clean mixer bowl, using the whisk attachment, whisk 8 egg whites until stiff but not dry. Fold egg white mixture into cake batter. Divide batter evenly between prepared cake pans. Bake, rotating pans halfway through, until cake batter springs back when touched but has no color on top, about 15 minutes. Transfer pans from oven to a wire rack to cool for 15 minutes. Remove cakes from pans, and return to racks to cool completely.
In the heatproof bowl of an electric mixer set over a pan of simmering water, whisk together egg yolks, whole eggs and sugar until thick and glossy, and sugar has dissolved. Transfer bowl to mixer fitted with the whisk attachment and whisk until mixture is cool to the touch, about 10 minutes. Add butter, one piece at a time, whisking until thoroughly combined. Add bourbon and whisk until incorporated. If frosting starts to separate, continue beating until it comes back together, about 5 minutes.
Cover raisins with warm water and soak until plumped, around 15 minutes. Drain.
Place one cake layer on a serving plate. Brush with about 2 tablespoons of bourbon to moisten. Spread with ¾ cup frosting and top evenly with ½ cup soaked raisins and ½ cup unsweetened coconut. Sprinkle with ⅓ of the chopped pecans and ⅓ of the chopped kumquats. Repeat process with 2 more cake layers in the same order ((frosting, raisins, coconut, pecans, kumquats). Top with remaining cake layer. Brush with remaining bourbon. Spread a thin coat of frosting over the top and sides of cake to cover. Chill for 20 minutes.
After cake is chilled, use remaining frosting to fully cover top and sides of cake. Serve.