• Preheat the oven to 350°F. Grease a 9x13-inch baking pan with butter or non-stick spray, then line it with parchment paper, allowing some overhang on the sides for easy removal. Set aside.
• Mix the dry ingredients. In a medium-sized bowl, whisk together the all-purpose flour, baking powder, and a pinch of sea salt. Set this mixture aside.
• Prepare the wet ingredients. In a large mixing bowl, use an electric mixer on medium speed to beat together the eggs, egg whites, and granulated sugar until light and fluffy, about 2–3 minutes. Add the vegetable oil, sour cream, and pure vanilla extract, and mix on medium speed until the mixture is smooth and fully combined.
• Combine wet and dry ingredients. With the mixer on low speed, gradually add the dry ingredients to the wet mixture in three parts, alternating with the buttermilk. Begin and end with the dry ingredients. Mix gently on low speed after each addition until just combined, ensuring the batter remains smooth without overmixing to keep the cake light.
• Add color. Stir in the green food dye, a few drops at a time, until the batter reaches the desired Grinch-inspired green hue.
• Bake the cakes. Pour the batter into the prepared 9x13-inch pan, spreading it evenly with a spatula. Bake in the preheated oven for 25–30 minutes or until a toothpick inserted into the center comes out clean. Allow the cake to cool in the pan for 10–15 minutes, then transfer it to a wire rack to cool completely.

Making the Green Cream Cheese Frosting

• Creaming the ingredients. In a large mixing bowl, beat the cream cheese with a hand mixer until smooth and creamy. Gradually add the sifted powdered sugar and mix until fully combined. Add the vanilla extract and green food dye, mixing until the frosting is a vibrant green color.
• Adjust consistency. If the frosting is too thick, add a teaspoon of milk at a time until it reaches the desired consistency. If too thin, add a little more powdered sugar.

Assembling the Grinch Cake

• Place the cake layer on a serving plate or cake stand. Spread an even layer of green cream cheese frosting on top.
• Decorate with red heart sprinkles and crushed candies to give the cake its Grinch-inspired charm. Enjoy this colorful cake!