This eggnog cake is so festive and perfect for the holidays! It's frosted with a spiced cream cheese buttercream, and topped with white chocolate ganache!
Preheat the oven to 350℉. Grease and flour three 8'' cake pans and line the bottoms with parchment paper. Set aside.
In a medium mixing bowl, combine the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Whisk to combine.
In a large mixing bowl, combine the eggs, granulated sugar, and brown sugar and whisk until smooth. Add the butter, vanilla, rum, sour cream, and eggnog and whisk until combined. Add the dry ingredients and mix with a rubber spatula until just combined. Pour the batter evenly into the pans and smooth out the tops with a spatula. Bake for 20-22 minutes or until a toothpick inserted comes out clean. Let the cakes cool for 10 minutes, then remove them from the pans and let cool the rest of the way on a cooling rack.
Make the frosting. Add the butter and cream cheese to the bowl of a stand mixer and whip on medium high for 2-3 minutes until light and fluffy. Reduce speed to low and gradually add the powdered sugar until combined. Add the vanilla, nutmeg, eggnog, and salt and increase speed to medium-high and whip for 4-5 minutes or until super fluffy.
To make the ganache, add white chocolate, heavy cream, and rum to a medium microwave safe bowl. Microwave for 20 seconds, stir, and then microwave for another 20 seconds or until completely melted. Stir until smooth and pourable. Let cool for 5-10 minutes.
To assemble the cake, place one layer on a plate or the cooling rack (just so you don't mess up the plate you are serving on, or the cake stand!), and spread the top with the frosting. Top with another layer and spread top with frosting. Top with the third layer and spread with another layer of frosting, leaving a little bit left for the sides of the cake. Use the leftover frosting to "half" frost the sides, to create a "semi-naked" effect. Use an offset spatula or bench scraper to smooth out the sides of the cake. Pour the cooled ganache over the cake and let it drip down the sides. Garnish with twigs, red berries, branches, sprinkles, crushed peppermint candies, sugared cranberries, or whatever your heart desires!