1½ (12 oz) packages cream cheese, at room temperature
3/4 cup sugar
1 cup pumpkin puree
1 egg plus 1 egg yolk
1/4 cup sour cream
1 tsp vanilla
1/4 teaspoon ground cinnamon
1/8 teaspoon fresh ground nutmeg
2 tbsp bourbon (optional)
1 15oz can pumpkin puree
2 cups sugar
1 cup vegetable oil
4 large eggs
1 tsp vanilla
2 cups all-purpose flour
2 teaspoons baking soda
1 teaspoon baking powder
2 teaspoons ground cinnamon
1/4 teaspoon ground nutmeg
1/2 teaspoon salt
Brown Sugar Buttercream
4 large egg whites
1 cup firmly packed dark brown sugar
1/4 teaspoon salt
1/4 tsp cream of tartar
1lb (4 sticks) unsalted butter, room temperature, cut into tablespoons
1 tsp vanilla (or you can use more bourbon, up to 1 tbsp)
For the cheesecake:
Butter an 8? pan with a removable bottom, and line the pan with parchment paper. Preheat oven to 350°. Arrange a pan of hot water on the bottom rack of the oven, and place another rack in the center.
In the bowl of a standing mixer fitted with the paddle attachment, beat together the cream cheese and sugar on low speed until smooth. Mix in the pumpkin, sour cream, cognac (if using) and spices, and beat together until combined, scraping down the sides frequently. Add the egg and egg yolk, and mix until incorporated. Pour the filling into the prepared pan and gently smooth down the top.
Bake the cheesecake on the center rack for about 30 minutes, or until the sides of the cake appear firm but the center still jiggles. Remove the cheesecake from the oven and allow it to cool before covering it with plastic wrap and placing it in the refrigerator. Allow it to refrigerate for at least 8 hours, or simply make it a day in advance. The long chill time allows the cheesecake to set properly.
For the cake:
Grease, flour, and line two 8-inch round cake pans and preheat the oven to 350°.
Combine the sugar, oil, eggs, vanilla, and pumpkin in the bowl of a standing mixer fitted with the paddle attachment, and mix well. Whisk together the remaining dry ingredients in a separate bowl. Reduce the mixer speed to stir and add the dry ingredients to the wet ingredients gradually. When the flour mixture has been fully added, increase the speed to medium, and beat until well combined.
Pour the cake batter into the prepared cake pans and bake for 30 to 35 minutes (until the top of the cake springs back when lightly touched). After about 10 or 15 minutes, turn the layers out onto racks to cool.
For the frosting:
In a heatproof bowl (I typically just use my metal mixing bowl), whisk together the egg whites, brown sugar, salt, and cream of tartar. Place the bowl over a pot of gently simmering water, and heat, whisking regularly, until the sugar has dissolved completely and the mixture is warm to the touch.
Fit your mixer with the whipping attachment and beat on medium-high until the egg mixture has cooled completely and stiff peaks form (about 10 to 15 minutes). Now, switch to the paddle attachment, and reduce the speed to medium-low. Add the butter one tablespoon at a time, until fully incorporated, then increase the speed to medium or medium high and beat the frosting until creamy and smooth.
Assembling the cake:
Level the cake layers, if necessary, for an even surface. Place a layer of pumpkin cake on your cake plate, and top the cake evenly with frosting. Place the cheesecake layer on top of the bottom layer of cake. Now, top the other layer of pumpkin cake with frosting, and then invert that layer onto the cheesecake layer so that the frosting is face down. Make sure to adjust the layers if necessary, so that the sides are even.
Cover the entire cake with a light crumb coat, then refrigerate until the crumb coat is firm, about 30 minutes or so. Frost and decorate the cake as desired using the rest of the buttercream.