Preheat your oven to 350°F. Prepare three 8-inch round cake pans by lining the bottoms with parchment paper cut to size, then coat the entire pans with cooking spray to prevent sticking.

In a large mixing bowl, combine cake flour, both sugars, baking soda, baking powder, nutmeg, and salt. Stir the dry ingredients together until thoroughly mixed.

In a separate bowl, whisk the eggs with the vegetable oil, eggnog, and vanilla extract until smooth and well blended.

Slowly incorporate the wet mixture into the dry ingredients, stirring gently just until combined. Avoid overmixing to keep the batter light and fluffy.

Divide the batter evenly among the three cake pans. For precision, use a kitchen scale to ensure equal amounts in each pan.

Bake for 20-25 minutes, or until the cakes have a light golden hue and a toothpick inserted into the center comes out clean or with just a few crumbs.

Allow the cakes to cool in their pans for about 10 minutes before gently turning them out onto a cooling rack. Let them cool completely before frosting.

With an electric mixer, beat the softened butter and vanilla extract together for 1-2 minutes until the mixture is smooth, light, and fluffy.

Gradually add the powdered sugar, one cup at a time, while keeping the mixer speed on low to avoid sugar clouds. Mix until all the sugar is incorporated.

Add the eggnog and continue beating until the frosting becomes creamy and spreadable. If it feels too thick, add more eggnog a teaspoon at a time. If it's too thin, slowly add extra powdered sugar, one tablespoon at a time, until it reaches the desired consistency.

Place one layer of cake on your serving dish. Spread a thin layer of frosting evenly over the surface.

Position the second cake layer on top, and again, apply a thin layer of frosting over it.

Finish with the third cake layer, and frost the entire cake with the remaining frosting. Use an offset spatula for a smooth finish or a piping bag for more detailed decoration.

Garnish with fresh or candied cranberries and sprigs of rosemary for a festive touch, slice, and enjoy!