Fluffy White Cake with Vanilla Buttercream

Servings two-layer, 8-inch cake

Author Rachel Conners

Ingredients

Fluffy White Cake

5 large egg whites 5 oz./150 grams, room temperature*
3/4 cup whole milk 180 mL/6 oz., room temperature*
2 1/4 teaspoons pure vanilla extract 12.5 mL
2 1/2 cups sifted cake flour 10 oz./285 grams–weighed after sifting
1 3/4 cups sugar 12 oz./350 grams
1 tablespoon + 1 teaspoon baking powder 19.5 grams
3/4 teaspoon salt 5 grams
12 tablespoons unsalted butter 6 oz./170 grams, room temperature and cut into cubes

Fluffy Vanilla Frosting**

3 sticks + 2 tablespoons 375 grams/13 oz. unsalted butter, softened and cut into cubes
3 cups sifted 480 grams/1 lb + 1 oz. confectioners’ sugar
2 tablespoons 30 mL heavy cream
2 teaspoons 10 mL pure vanilla extract
Gel food coloring if desired (I used a mix of turquoise and sky blue to achieve the color you see)
Pinch of salt

Instructions

For the cake

Preheat oven to 350°F. Grease, line with parchment, and flour two round 8-inch pans.
In a medium bowl or measuring cup, combine and stir the egg whites, 1/4 cup of milk, and the vanilla. Set aside.
In the bowl of an electric mixer fitted with the paddle attachment, combine the dry ingredients together on low speed (I use the “stir” setting on my mixer) for 30 seconds.
Add the butter and remaining 1/2 cup of milk, and mix on low speed until just moistened. Increase to medium speed and mix for 90 seconds.
Scrape the sides of the bowl and begin to add the egg mixture in 3 separate batches; beat on medium speed for 20 seconds after each addition.
Divide the batter in two, spreading it into the prepared pans evenly with a small offset palette knife. If you have a kitchen scale, weigh to ensure 2 even layers.
Bake 25-35 minutes or until a cake tester comes clean when inserted into the center. Be so careful to not overbake! Check cake at 20 minutes, but not before, and once you feel it’s almost ready, set the timer for 2 minute intervals. Mine took about 29 minutes to be done, so keep a close eye on them! Let cool on racks for 10 minutes before loosening the sides with a small metal spatula, and invert onto greased wire racks. Gently turn cakes back up, so the tops are up and cool completely.
You can wrap tightly and store at room temperature for up to 2 days, refrigerator for up to 5 days, or frozen for up to 2 months, but I like to make the same day as serving, so if you are serving that day, go ahead and frost them!

For the frosting

In the bowl of an electric mixer fitted with the paddle attachment, whip butter for 8 minutes on medium speed (I use “4" on my KitchenAid). Butter will become very pale & creamy.
Add remaining ingredients and mix on low speed for 1 minute, then on medium speed for 6 minutes. Frosting will be very light, creamy, and fluffy.
Best used right away.

Assembly

Place bottom cake layer on cake plate or round thin cake board.
Place 1 cup of frosting on top, and spread evenly with a small offset palette knife.
Gently place 2nd cake layer face down on top. Place a generous scoop of frosting on top, spreading evenly with a small offset palette knife and working your way down the sides until you have a thin layer of frosting over the entire cake - a crumb coat. Chill until set — about 30 minutes.
Remove from refrigerator and frost however you like! If you're doing roses (or other piping job), add more powdered sugar (I used about 1 1/2 cups) to stiffen the frosting and follow the instructions here.
Store in a cake keeper at room temperature for up to 2 days, or in refrigerator for up to 5 days. Best eaten day 1.

Notes

Cake recipe adapted from Sweetapolita, and frosting recipe adapted from Sweetapolita

Note: If you're using a kitchen scale, you can use the original recipe, which calls for 1 cup of milk and 6 egg whites. This is the recipe I use, but it's a bit finicky and tends to curdle if only a tiny bit of extra liquid is added. I would recommend only using this amount of liquid if you are weighing all of your ingredients, or it's very easily to mess up!

*Note: I multiplied this frosting recipe by 1.5x to make the roses, as they use more frosting than a simple frosting job. If you're going to try the roses, I recommend doing this, otherwise keep the recipe as is.