01 - Preheat oven to 350°F. Grease and flour two 9-inch round cake pans, lining bottoms with parchment paper.
02 - In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, and cocoa powder until well blended.
03 - In a separate bowl, whisk buttermilk, oil, eggs, vanilla, vinegar, and green food coloring until completely smooth.
04 - Pour wet ingredients into dry ingredients. Mix gently until just combined—avoid overmixing to maintain tender texture.
05 - Divide batter evenly between the two prepared cake pans, smoothing tops with a spatula.
06 - Bake for 28 to 32 minutes until a toothpick inserted in the center emerges clean.
07 - Let cakes rest in pans for 10 minutes, then invert onto wire racks to cool completely before frosting.
08 - Beat cream cheese and butter until creamy and smooth. Incorporate powdered sugar, vanilla, and salt; continue beating until fluffy and spreadable.
09 - Position first cake layer on serving plate. Spread frosting evenly over surface. Place second layer on top, then frost top and sides completely.
10 - Decorate with green sprinkles or edible glitter if desired for festive presentation.