Preheat oven to 350°F. Line two 8-inch cake pans with parchment paper and set aside.
In a large bowl, whisk together flour, baking soda, baking powder, and salt.
In a separate large bowl, whisk together the sugar and vegetable oil until combined. Then whisk in the eggs, one at a time, until combined. Whisk in the vanilla.
Slowly whisk in ⅓ of the flour mixture then ⅓ of the buttermilk until combined. Then repeat twice, alternating the flour mixture and the buttermilk mixture, until everything is combined.
Then whisk in the green food coloring. Start by adding about 10 drops, whisking, then adding more as needed until the color reaches the color of green you like. For me, that's usually between 20 and 30 drops.
Pour the batter evenly between the two prepared cake pans. Bake at 350°F for 30 to 40 minutes, until a toothpick inserted into the center of the cakes comes out clean. While the cakes are baking, make the frosting.
Make the Cream Cheese Frosting
In a stand mixer using the paddle attachment (or using a hand mixer and a large bowl) cream the butter and cream cheese together until light yellow and fluffy, about 3 to 5 minutes. Use a spatula to scrape down the sides as needed.
Beat in the salt and vanilla.
Then beat the powdered sugar in, one cup at a time, until fully combined, scraping the sides down with a spatula as needed. Set aside until the cakes are done baking. (See NOTES for helpful tips.)
Cooling Time
Once the cakes are done, remove from the oven and allow the cakes to cool in the pans for about 20 minutes. Then invert the cake pans onto a cooling rack and allow the cakes to cool at room temperature until completely cooled.
Assemble
Once the cakes are cool, use an offset spatula to spread the frosting over the cakes. Decorate as you wish!
Notes
Makes: one 8-inch two-layer cake with approximately 12 servings.Tips:
Make sure your eggs, butter, and cream cheese are all at room temperature before you start baking. Take them out of the refrigerator about 30 minutes before you are ready to start.
Frosting tips:
If your frosting is too thin, add more powdered sugar.
If your frosting is too thick, add a little milk, one tablespoon at a time.
Make sure the cakes are completely cool before frosting. You can also refrigerate the cakes before frosting them.