Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla extract and green food coloring.

In a separate bowl, whisk together the flour, baking powder, and baking soda. Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined.

Pour the batter evenly into the prepared pans.

Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.

In a large bowl, beat the softened butter until light and fluffy. Gradually add the powdered sugar, beating until smooth.

Add the heavy cream and vanilla extract and beat until light and fluffy.

Once the cakes are completely cool, frost the top of one layer with frosting. Place the second layer on top and frost the entire cake.

Decorate as desired.