For the Cakes:

1. In small bowl, mix egg whites and 1/4 cup buttermilk. Set aside.
2. In mixing bowl, beat butter and sugar until creamy, about 2-3 minutes. Add in dry ingredients and mix until combined. Slowly add in egg white mixture. Beat in remaining buttermilk.
3. Bake in a 350 degree oven for 25-30 minutes.
4. Remove and cool on wire rack.

For the Cheesecake:

1. Preheat oven to 325 degree. Using a large roasting pan on the lower 1/3 of the oven, preheat the pan. Prepare springform pan by wrapping bottom of pan (outside) with double layer of foil. Spray pan with nonstick baking spray and line bottom (inside) with a circle of parchment paper. Meanwhile, boil several cups of water to use later.
2. Beat cream cheese with sugar for 2-3 minutes until creamy. Add in salt and egg, one at a time, beating well after each addition. Beat in sour cream, heavy cream and remaining ingredients.Pour into prepared 9inch springform pan. Place pan in center of preheated roasting pan. Pour boiling water, slowly, into pan, utnil about one inch of water comes up the sides. Bake cheesecake for 45 minutes. Turn oven off and let cheesecake sit for an additional 30 minutes in oven. Remove and cool completely.
3. When cooled remove from springform pan and place in freezer for one hour, or overnight until ready to assemble cake.

For the Frosting:

1. Beat butter for 3 minutes until fluffy. Add in nutmeg, rum flavoring, powdered sugar and eggnog. Beat for an additional 3-5 minutes until fluffy.

To assemble Cake:

• Lay one spice cake on cake plate. Top with cheesecake then second layer of spice cake. Frost with eggnog frosting! ENJOY!