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

In a large bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.

In another bowl, beat the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes.

Incorporate the eggs one at a time into the butter-sugar mixture, mixing well after each addition. Stir in the orange zest.

In a separate bowl, mix the buttermilk and fresh orange juice.

Gradually add the dry ingredients to the butter mixture in three parts, alternating with the buttermilk mixture. Begin and end with the flour mixture. Mix just until incorporated.

Pour the batter evenly into the prepared pans and bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.

Let the cakes cool in the pans for about 10 minutes, then transfer to a wire rack to cool completely.

In a medium bowl, beat softened cream cheese and butter until smooth and creamy.

Gradually add in the powdered sugar, mixing on low speed. Once incorporated, add in the vanilla extract and orange juice, mixing until smooth.

Once the cake layers are completely cooled, spread a generous amount of frosting on top of one layer. Place the second layer on top and frost the entire cake. Decorate with additional orange zest on top if desired.