Preheat oven to 350°F, 177C or gas mark 4. Grease 3 9 inch cake pans and set aside.
In a mixing bowl combine the flour, baking powder, baking soda, salt, pepper, nutmeg, allspice, cinnamon, ginger, and cloves. Whisk to make sure everything is evenly combined and set aside.
In the bowl of the stand mixer with a paddle attachment add the brown sugar, sugar and vegetable oil. Mix on low until all of the them have been incorporated. Add the sour cream and mix until smooth. Increase the speed to medium high and add the eggs one at a time waiting a minute between each egg. Add the molasses and vanilla.
Reduce the speed to low and add half the flour mixture, mix until just combined and then add all of the buttermilk. Once combined add the remainder of the flour mixture and mix until just combined.
Divide the cake batter evenly between the three pans and bake until a toothpick or knife inserted in the middle comes away clean, about 25-30 minutes.
Allow the cakes to cool in the pan for at least 10 minutes before turning the cakes onto a cooling rack. Allow to cool completely before icing the cake.
Crema Cheese Eggnog Buttercream
Cream the butter and cream cheese on medium-high speed until pale and fluffy. Reduce the speed to low and add the powdered sugar. Once all of the sugar has been incorporated then increase the speed to medium.
Add the nutmeg and then add the eggnog one tablespoon at a time until you get the desired consistency.