Decadent Bourbon Butterscotch Layer Cake

Bourbon Cake:

• ¾ cup unsalted butter , room temperature (170 grams)
• ¾ cup granulated sugar (150 grams)
• ½ cup + 2 tablespoons packed light or dark brown sugar (135 grams)
• 1 teaspoon vanilla extract
• 2 large eggs
• 2 large egg yolks
• 2 ¼ cups cake flour (270 grams)
• 1 ½ teaspoon baking powder
• ¾ teaspoon baking soda
• ½ teaspoon salt
• ½ teaspoon nutmeg , preferably freshly grated
• 1 cup buttermilk (250 ml)
• ¼ cup bourbon whiskey (60 ml)

Bourbon Butterscotch:

• 6 tablespoons unsalted butter , cubed (85 grams)
• ¾ cup packed light or dark brown sugar (160 grams)
• 1 teaspoon corn syrup
• ½ teaspoon salt
• ¼ cup heavy cream (60 ml)
• ½ teaspoon vanilla extract
• 3 tablespoons bourbon whiskey

Butterscotch Swiss Meringue Buttercream:

• 5 large egg whites
• 1 ¼ cup granulated sugar (250 grams)
• 2 cups unsalted butter , cubed and at room temperature (450 grams)
• 2 teaspoons vanilla extract
• ¼ teaspoon salt
• ½ cup bourbon butterscotch , from above recipe

To Make the Cake:

1. Preheat oven to 350 degrees F (175°C). Generously grease three (or two if only two are available) 6-inch round cake pans. Line the bottoms of the pans with parchment paper to prevent sticking. (See Notes for alternative pan sizes.)
2. In the bowl of a stand mixer equipped with a paddle attachment, cream together the softened butter, granulated sugar, and brown sugar on high speed until the mixture is light, pale, and fluffy, a process that typically takes about 3-4 minutes. Remember to scrape down the sides of the bowl periodically to ensure even mixing.
3. Incorporate the vanilla extract into the creamed mixture. Then, add the large eggs and egg yolks one at a time, ensuring each addition is fully mixed in before adding the next. This helps to create an emulsion and adds to the cake’s structure.
4. In a separate medium bowl, whisk together the cake flour, baking powder, baking soda, salt, and freshly grated nutmeg. Gradually add these dry ingredients to the wet mixture in three alternating additions with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined, scraping down the bowl as needed to ensure no dry pockets remain. Finally, gently mix in the bourbon whiskey until uniformly distributed.
5. Divide the prepared cake batter evenly among the greased and lined cake pans. Bake for approximately 25 minutes, or until the edges are golden brown and the tops spring back when lightly touched in the center. A wooden skewer inserted into the center should come out clean.
6. Allow the cakes to cool in their pans on a wire rack for about 15 minutes. After this initial cooling, carefully invert them onto the wire rack to cool completely. If you only have two pans, you can bake in two batches, washing and preparing a pan for the third layer after the first two are done. Ensuring the layers are fully cooled is crucial for assembly.
7. Once completely cooled, wrap each cake layer tightly in plastic wrap and chill in the refrigerator until you are ready to assemble the cake. Chilling the layers makes them firmer and easier to handle, especially when frosting.

To Make the Bourbon Butterscotch:

1. In a medium-sized heavy-bottomed saucepan, combine the cubed unsalted butter, packed brown sugar, corn syrup, and salt. Place the saucepan over medium heat, stirring frequently until the butter has completely melted, the sugar has dissolved, and the mixture appears smooth and well-combined. This should take approximately 5 minutes.
2. Carefully pour in the heavy cream. The mixture may sputter slightly at first; whisk continuously until it becomes smooth. Increase the heat to medium-high and bring the butterscotch mixture to a rolling boil. Allow it to simmer gently for about 5 minutes, or until it has thickened to a syrupy consistency, coating the back of a spoon.
3. Remove the saucepan from the heat. Stir in the vanilla extract and bourbon whiskey. Mix until thoroughly combined. Set the butterscotch aside to cool completely to room temperature before using it in the buttercream or for drizzling. It will thicken further as it cools.

To Make the Swiss Meringue Buttercream:

1. Combine the egg whites and granulated sugar in the clean metal bowl of a stand mixer. Place this bowl over a small saucepan of simmering water (ensure the bottom of the bowl does not touch the water). Whisk the mixture occasionally until it reaches a temperature of 160°F (71°C), or until it is very hot to the touch and all the sugar crystals have completely dissolved.
2. Carefully remove the bowl from the heat and attach it to your stand mixer. Using the whisk attachment, beat the meringue on high speed until it forms stiff, glossy medium peaks. This process usually takes about 8 minutes. The bowl should feel cool to the touch. Reduce the mixer speed to medium-low and gradually add the cubed, room-temperature butter, one tablespoon at a time. Allow each addition to fully incorporate into the meringue before adding the next. The mixture may look curdled at first, but keep beating; it will come together.
3. Once all the butter is incorporated, add the vanilla extract and salt. Increase the mixer speed to high and beat for another 1-2 minutes until the buttercream is perfectly smooth, light, and creamy.
4. Finally, add ½ cup of the cooled bourbon butterscotch sauce to the buttercream all at once. Mix on medium speed until the butterscotch is fully incorporated and the buttercream is uniform in color and consistency. Reserve the remaining butterscotch for drizzling.

To Assemble the Cake:

1. For an even more impressive visual and texture, you can carefully cut each of the three chilled cake layers in half horizontally using a serrated knife or a cake leveler. This optional step will yield a stunning six-layer cake.
2. Place one cake layer onto your desired serving plate or cake stand. Spread an even layer of buttercream over the top – use about ½ cup if you have three thick layers, or ⅓ cup if you opted for six thinner layers. Carefully place another cake layer on top and repeat the frosting process until all cake layers are stacked and frosted.
3. Once all layers are stacked, use an offset spatula to apply the remaining buttercream to the top and sides of the cake, smoothing it out for a neat finish.
4. Chill the assembled cake in the refrigerator for at least 30 minutes. This helps the buttercream to set, making it easier to handle and ensuring neat slices.
5. Just before serving, gently warm the remaining bourbon butterscotch sauce in the microwave for 20-30 seconds, or until it reaches a pourable consistency. Using a spoon, artfully drizzle the warm butterscotch over the top of the chilled cake, allowing it to cascade down the sides. Serve the cake immediately, or keep it chilled until ready to present. If chilled, allow the cake to come to room temperature for approximately 30 minutes before slicing for the best texture and flavor. Store any leftover cake in an airtight container in the refrigerator for 3-5 days.

NOTES:

• For a shorter, wider cake, this recipe can alternatively be baked in two 8-inch round pans. This batter also yields approximately 2 ½ dozen delicious cupcakes. Adjust baking time accordingly for cupcakes (typically 18-22 minutes).
• To prepare ahead, cake layers can be baked in advance. Store them tightly wrapped in plastic in the refrigerator for up to 5 days, or double-wrapped in the freezer for up to 2 months. Thaw frozen layers in their wrappings at room temperature before assembling the cake.
• Any unused bourbon butterscotch sauce can be stored in an airtight container in the refrigerator for several weeks, ready to enhance other desserts or beverages.

Recipe slightly adapted from Layered: Baking, Building, and Styling Spectacular Cakes by Tessa Huff.