Prepare the Cake Batter: In a mixing bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and salt. In a separate bowl, blend the granulated sugar, vegetable oil, eggs, vanilla extract, buttermilk, white vinegar, and green food coloring until smooth. Gradually combine the dry ingredients with the wet, mixing gently until just incorporated.
Bake the Cake: Preheat your oven to 350°F (175°C). Grease and flour your cake pans. Pour the prepared batter evenly into the pans and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean. Allow the cakes to cool in the pans for about 10 minutes before transferring them to wire racks.
Make the Cream Cheese Frosting: In a mixing bowl, beat the softened unsalted butter and cream cheese together until smooth and creamy. Gradually add the sifted powdered sugar and mix well. If desired, add milk or heavy cream to achieve your preferred frosting consistency.
Assemble the Cake: Once the cake layers have completely cooled, place one layer on a serving plate. Spread a generous layer of cream cheese frosting on top. Carefully place the second layer on top and frost the entire cake for a beautiful finish.
Decorate: Sprinkle green sprinkles atop the frosted cake for an added festive touch. For a professional finish, use a cake turntable to help you frost evenly.