Preheat the oven to 350°F. In a large mixing bowl, whisk together the flour, baking powder, baking soda, and salt. In another bowl, beat the butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract. Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients.

Pour the batter into a greased and floured 9-inch round cake pan. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.

In a large bowl, beat the softened butter until smooth. Gradually add the powdered sugar, beating until well incorporated. Stir in the vanilla extract and milk, adding more milk if necessary to achieve a spreading consistency.

Once the cake is completely cool, spread a thin layer of frosting over the entire cake as a crumb coat. Chill the cake for 15 minutes, then apply a thicker layer of frosting for a smooth finish.

Using edible markers or piping gel, draw a clock face on the cake. Mark the numbers and add clock hands pointing to midnight. Be creative with your design for a festive touch.

Slice the cake into 8 pieces and serve as the countdown begins. Pair with non-alcoholic beverages for a delightful treat.

Store leftover cake in an airtight container at room temperature for up to 3 days or refrigerate for up to a week.