Ingredients

• Cake
• 2 1/2 cups all-purpose flour
• 1 1/2 teaspoons baking soda
• 3/4 teaspoon salt
• 3/4 cup (1 1/2 sticks) butter, softened
• 1 1/2 cups sugar
• 3 eggs
• 1 1/2 cups buttermilk
• 1 1/2 teaspoons vanilla
• 1 tablespoon orange zest


• Orange Frosting
• 1/2 cup butter, softened
• 4 1/2 cups confectioner's (powdered) sugar
• 1/4 cup plus 1 tablespoon freshly squeezed orange juice
• 1 tablespoon orange zest

Directions

Heat oven to 350° F.

In a medium mixing bowl, whisk together flour, baking soda and salt. Set aside.

In an electric mixer bowl, add butter and sugar and beat until smooth and creamy, stopping once to scrape sides and bottom of bowl. Add 1/2 of the flour and mix just until blended. Add buttermilk, vanilla and orange zest and mix again just until blended. Add remaining flour and mix until thoroughly blended and smooth.

For a 2-layer cake, pour equal portions of cake batter into 2 greased 9-inch-round cake pans. For a 3-layer cake, pour equal portions of cake batter into 3 greased 8 or 9-inch-round cake pans. For a 4-layer cake, simply pour equal portions of cake batter into 2 greased 8 or 9-inch-round cake pans, then cut each baked and cooled layer in half horizontally to make 4 layers. If you are making a sheet cake, pour batter into a greased 9x13-inch rectangular cake pan.

Before baking, smooth cake batter with a rubber spatula or butter knife if necessary to flatten batter so cake rises as evenly as possible over entire top.

Bake cake according to times specified below:
2-layer cake: 25-30 minutes (bake in 2 pans)
3-layer cake: 20-25 minutes (bake in 3 pans)
4-layer cake: 25-25 minutes (bake in 2 pans, then cut each cake in half horizontally after baked)
Sheet cake: 45-50 minutes (bake in 9x13-inch rectangular cake pan)

Note: Oven temperatures may vary, so watch cake closely toward end of baking time, and bake just until a toothpick inserted into center of cake(s) comes out clean.

Allow cake to completely cool before applying frosting.

Orange Frosting
Place butter and confectioner's (powdered) sugar into an electric mixer bowl (may also be beaten with a handheld electric mixer). Mix on low until slightly blended, then add orange juice (or orange liqueur) and orange zest and beat until smooth and creamy. Apply to cooled cake.

Applying Frosting to Layered Cakes
Save and set aside the most perfect baked cake for the top layer. If any cakes puffed up in one spot during baking, simply cut off the obvious mound with a bread knife (a slight amount of rising toward the center and drooping towards the outer sides of the cake is normal, so only cut off the obvious mound that will not allow the cake layers to stack easily). (Tip: The cut-off mounds are a great way to test how the cake tastes!) Apply frosting to each layer (about 1/8 to 1/4-inch-thick, depending on preference). Place saved top cake layer on top of frosted layers and apply frosting, using any swirl design you prefer. Apply frosting to the sides, using the same swirl patter you used on the top of cake.

If desired, garnish top of cake (entire top or only around edges) with finely grated orange peels (the small holes in a cheese grater will produce nice orange peels).