Ingredients
Equipment
Method
- Preheat your oven to 350 degrees F (176 degrees C). Grease and flour three or four 8 or 9-inch round cake pans. Line the bottoms with parchment paper, also greased.
- Separate the 4 whole eggs. Place the yolks in a small bowl. Add the egg whites from the 4 whole eggs and the 4 additional egg whites to the bowl of a standing mixer fitted with the whisk attachment. Beat the egg whites until stiff peaks form. Transfer the beaten egg whites to a separate bowl.
- Clean and dry the standing mixer bowl. Fit the mixer with the paddle attachment. Cream the butter and sugar until light and fluffy, about 6 minutes. Scrape down the sides of the bowl as needed.
- Add two egg yolks and beat until incorporated, about 20 seconds. Scrape down the sides. Add the remaining two egg yolks, beat until incorporated, about 20 seconds, and scrape down the sides again.
- In a separate bowl, whisk together the cake flour, baking powder, baking soda, and salt.
- In a large measuring cup, stir together the champagne, buttermilk, and vanilla extract.
- With the mixer on low speed, add the dry ingredients and the liquid ingredients alternately, in four additions. Begin and end with the dry ingredients. Mix on low to medium speed just until each addition is incorporated. Scrape down the sides of the bowl as needed.
- Using a rubber spatula, gently fold the beaten egg whites into the batter until just incorporated.
- Divide the batter evenly into your prepared pans. Bake for 30-40 minutes for 3 layers, or 25-30 minutes for 4 layers. The cakes are done when golden brown, pulling away from the sides of the pan, and a toothpick inserted into the center comes out with moist crumbs attached.
- Let the cakes cool in the pans on wire racks for 5 minutes. Then, gently turn them out onto the wire racks to cool completely. Wrap tightly in plastic wrap if not frosting immediately. Layers can be stored at room temperature for 1 day or frozen for up to 2 months.
- For the strawberry and champagne Italian meringue buttercream: Pour 1 cup of champagne into a small saucepan and boil until reduced to 1/2 cup. Let it cool completely. Slowly beat the cooled champagne reduction into a prepared batch of Italian Meringue Buttercream.
- Remove about two-thirds of the buttercream from the mixing bowl. Add the pureed strawberries to the remaining buttercream and beat until fully incorporated.
Notes
A note on cake flour substitution: If you do not have cake flour, you can make your own by removing 2 tablespoons of flour for every cup of all-purpose flour, then sifting the flour and cornstarch together.