• Preheat your oven to 325 degrees F
• Sift flour, baking powder, baking soda, salt, cinnamon, and nutmeg into a medium bowl. Set aside.
• Spray three 6-inch cake pans with non-stick spray. Set aside.  
• Into the bowl of an electric mixer with the paddle attachment, beat butter and oil together for 3-4 minutes until they are completely unified.
• Slowly add sugar into the mixture and beat on medium to high speed until light and fluffy (about 2 minutes) Scrape down the sides of the bowl. 
• With the mixer on low speed add egg whites in one at a time followed by the vanilla. Beat on high until mixture is smooth and light in colour.
• With the mixer on low speed, add one third of the flour mixture into the bowl and mix until just combined. Scrape down the bowl and add one half of the eggnog and again mix until just combined. Repeat this process. Begin and end with the flour mixture. Do not over mix or your cake will become quite dense.
• Distribute cake batter evenly between three 6-inch cake pans. I like to use a kitchen scale to ensure batter is divided equally.
• Bake for 35-38 minutes, or until knife comes out clean. Each oven is slightly different, so I suggest setting your timer to 30 minutes and watching carefully from there!
• Cool on cooling rack for 10 minutes before inverting and removing cakes from can pan to cool completely. 

Cinnamon Buttercream Frosting

• In the bowl of an electric stand mixer with the paddle attachment, cream butter for 3 minutes on high speed.
• Scrape down the sides of the bowl. With the mixer on low speed add in powdered sugar 1 cup at a time.
• Scrape down the sides of the bowl and add in cinnamon.
• With the mixer on low speed, add in heavy cream. Mix until combined. Scrape down the sides of the mixer.
• Turn mixer to medium to high and mix for 3-4 more minutes. Buttercream should be light, fluffy, and easily spreadible.