Instructions

For the Cake:

1. Preheat the oven to 350°F. In a large mixing bowl, combine the sugar, vegetable oil, eggs, and vanilla extract. Beat on medium speed until the eggs and oil are well incorporated and the batter is lighter in color, about 2 minutes.Scrape down the bowl as needed. Next mix in the sour cream and orange zest and beat until well combined.
2. In a separate bowl combine the dry ingredients. Alternate adding the dry ingredients and the wet ingredients (buttermilk and champagne). Beat on low speed until the flour starts to incorporate and all ingredients are added. Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed.
3. Pour the batter in two 9-inch round baking pans lined with a Silpat baking mat and bake at 350°F for 18-22 minutes, keeping a careful eye on the baking during the last few minutes. Remove from the oven and allow to cool completely. Test the cake for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, your cake is done. Allow the cake to cool for approximately 10 minutes and remove the cake from the pan.
4. Repeat the above steps to make the next two layers.

For the Frosting:

1. Combine the granulated sugar and egg whites in your stainless-steel mixer bowl (or any heat-proof glass or metal bowl). Attach a candy thermometer to the side of the bowl.
2. Set the bowl over top of a saucepan with water, just enough to cover the bottom of the pot. You do not want the water to boil and touch the bottom of your mixing bowl.
3. Heat the mixture over medium to medium-low heat, stirring constantly to prevent the egg whites from cooking. Heat the mixture to 140°F. When it reaches 140°F, the sugar should be dissolved in the egg whites. You can test this by placing a drop on your fingertips and rubbing them together.
4. The mixture should be completely smooth.
5. Transfer the mixing bowl to your stand mixer. Using the wire whisk, beat the egg whites. Start on low speed and increase the speed to medium speed after 2 minutes.
6. Beat for approximately 10 minutes on medium speed until your frosting turns white as the egg whites are whipped and the body of the meringue starts to form peaks that are thick, glossy, and soft.
7. After you have beat the meringue for a total of about 10-15 minutes, the bottom of your mixing bowl should be cooled completely. Scrape down all sides and bottom of the bowl.
8. Slice the butter into 1-tablespoon pieces. Switch to the paddle attachment on your mixer. Beat at a medium-low speed and slowly add the butter 2 tablespoons at a time, ensuring it is mixed well after each addition. The frosting may appear curdled at this point; that’s okay.
9. Add the vanilla bean paste and orange zest and continue beating on medium speed for about 3-5 minutes until the frosting is smooth and silky.