Step 1: Prepare the Batter

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and line your cake pans.
2. Combine Dry Ingredients: In a mixing bowl, sift together the cake flour, baking powder, and salt.
3. Cream Butter and Sugar: In another bowl, use an electric mixer to cream the softened butter and granulated sugar until light and fluffy.
4. Add Eggs and Vanilla: Beat in the eggs one at a time, then add the vanilla extract, mixing until well combined.
5. Incorporate Dry Ingredients: Gradually add the dry ingredients to the butter mixture, alternating with the milk, beginning and ending with the dry ingredients. Mix until just combined.
6. Add Food Coloring: Add green food coloring to achieve the desired shade of green. Mix until the color is evenly distributed.

Step 2: Bake the Cakes

1. Divide Batter: Pour the batter evenly into the prepared cake pans.
2. Bake: Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
3. Cool: Allow the cakes to cool in the pans for 10 minutes, then transfer to a cooling rack to cool completely.

Step 3: Frost and Decorate

1. Prepare Frosting: While the cakes are cooling, prepare the frosting and dye it green with food coloring.
2. Level the Cakes: Once the cakes are completely cool, trim the tops to create an even surface.
3. Apply Crumb Coat: Apply a thin layer of frosting to the cakes to trap any crumbs. Chill the cakes for 15 minutes.
4. Final Frosting Layer: Apply a thicker layer of frosting, smoothing it out with a spatula or cake smoother.
5. Decorate: Use piping bags and tips to add details, such as the Grinch’s face, using black icing for features and edible eyes. Add red heart-shaped sprinkles if desired.