Preheat the oven to 350 degrees. Prep 3-8″ round pans pans with flour or parchment paper and set aside.

Combine the flour, cocoa powder, baking soda, baking powder, and salt in a medium bowl. Set aside.

Add the sugar with the eggs in a mixing bowl. Beat on medium speed until combined and fluffy. Stir in the buttermilk, oil, and vanilla until combined.

Alternate mixing in the dry ingredients with the coffee. Scrape the sides of the bowl and stir 1 minute more.

Divide evenly between the three pans, approximately 16 oz per pan.

Bake 18 to 20 minutes or until a toothpick comes out clean when poked in the middle.

Let the cakes cool 20 minutes. Turn out onto a cooling rack and continue cooling.

Add the butter into the bowl of an electric mixer. Using the paddle attachment, beat for 2 to 3 minutes or until the butter is smooth. Scrape the sides of the bowl with a spatula.

Add the powdered sugar, one cup at a time, and continue to mix until incorporated.

Stir in the cream and vanilla.

Scrape the sides of the bowl. Increase the speed to medium and beat for 5 minutes or until light and fluffy.

Scoop out 1/2 cup of the frosting and place in a small bowl.

Use a pink food coloring for the larger amount of frosting and green for the 1/2 cup.

Place one cooled cake onto a cake plate.

Top with 1 cup frosting or chocolate ganache. Spread evenly.

Add the second cake. Now, you can stop here or add a third layer.

Frost the outside of the cake with a spatula, making sure to leave it roughly finished.

Using the spatula, run it across the top creating the swirl line.

Place the green frosting into a piping bag. Snip a small hole in the end.

Carefully write your Happy Birthday greeting with the frosting across the top of the cake.