Rainbow Cake

By Tested and perfected in the Sur la Table kitchen
Images
Rainbow Cake
Ingredients
RAINBOW CAKE
  • Butter for greasing cake pans, at room temperature
  • 5 large eggs, separated, at room temperature
  • 8 ¾ ounces (1 ¼ cups) granulated sugar, divided
  • 6 1/3 ounces cake flour (1 ½ cups), sifted
  • 1 tablespoon baking powder
  • 1 teaspoon fine kosher salt or fine sea salt
  • 4 ounces (½ cup) lukewarm water
  • 4 ounces (½ cup) vegetable oil
  • 2 tablespoons vanilla extract
  • 1/8 teaspoon red, orange, yellow, green, blue and violet gel food colorings
  • ½ cup rainbow sprinkles, for decorating

BUTTERCREAM FROSTING
  • 6 large egg whites, at room temperature
  • 10 ½ ounces (1 ½ cup) granulated sugar
  • 1 ½ pounds (6 sticks) unsalted butter, chilled, cut into 1" pieces
  • ½ tablespoon vanilla bean paste, vanilla extract, or almond extract
  • ½ teaspoon fine kosher salt

Procedure
RAINBOW CAKE For best results, it is best to plan on a 2-day process from start to finish. You will need a minimum of 3, 6" cake pans to make this recipe. If using 3 cake pans, prepare two ½ recipes. Preheat oven to 350°F and position racks in upper and lower thirds of the oven. Butter, flour and line bottom of 6, 6" round cake pans with parchment paper.

To prepare batter: To the bowl of a stand mixer fitted with a whisk attachment add the egg whites. On medium speed, beat whites until foamy. On medium speed, gradually add ½ cup sugar to whipping egg whites. Once all sugar has been added, increase speed to medium-high and beat until soft peaks form. Carefully transfer whites into a clean mixing bowl, do not deflate.

Wipe stand mixer bowl clean. To clean stand mixer bowl fitted with a paddle attachment, add flour, remaining ¾ cup sugar, baking powder and salt. On medium-low speed, add lukewarm water into dry ingredients; increase speed to medium and add oil, egg yolks and vanilla. Beat until mixture is smooth and no streaks remain, scraping down sides of bowl with a silicone spatula as needed. Carefully fold whites into batter in 3 additions, do not deflate batter.

Divide batter evenly between six mixing bowls, each portion will weigh 5 ½ ounces. Add a scant 1/8 teaspoon gel food coloring to each bowl and fold dye throughout batter, do not deflate batter. Adjust vibrancy of color by adding more dye and folding carefully. Pour each colored batter into a prepared cake pan. Using an offset spatula, level top of batter.

Transfer cakes to preheated oven, bake until tester inserted into center comes out clean, 12 to 15 minutes. Cool cakes in pans, 10 minutes. Turn cakes out of pans onto wire cooling racks and cool completely.

Recipe variations: To flavor batter, add 1 teaspoon pure extract such as strawberry, orange or lemon.

BUTTERCREAM FROSTING

Velvety smooth, buttercream is the king of frostings. This version is a Swiss meringue buttercream, which simply means that the egg whites and sugar are heated together before beating. The buttercream can also be flavored in many ways, which makes it very versatile. Any leftover frosting freezes beautifully; it simply needs to be thawed to room temperature and re-whipped to be used another day.

To the bowl of a stand mixer, add egg whites and sugar; whisk to blend. Bring 2 inches of water to a simmer in a medium saucepan. Place bowl with whites and sugar over simmering water and heat, whisking constantly, until mixture reaches 160°F (hot to the touch) on an instant-read thermometer. Remove mixture from heat and attach bowl to a stand mixer fitted with a whisk attachment. Whisk mixture on high speed until it cools to room temperature, is light and billowing, and resembles marshmallow fluff. If mixture is warm, it will melt butter. Test temperature of meringue by touching the bottom exterior of bowl, it should feel room temperature.

Replace whisk attachment with paddle attachment. With mixer on medium-high speed, add chilled butter, a couple of tablespoons at a time, allowing each addition to blend in fully before adding next. Halfway through adding butter, stop mixer and use a silicone spatula to scrape down sides of bowl thoroughly. Continue to whip until all butter has been added and mixture is velvety and smooth. Add vanilla bean paste and salt, whip to incorporate.

Keep buttercream in an airtight container in refrigerator for up to 1 week or in freezer for up to 2 months. Let buttercream come to room temperature and re-whip in the mixer with paddle attachment before using.

Recipe variations: Buttercream can be flavored with melted and cooled chocolate, pureed fruit, natural extracts, toasted nuts, and salted caramel. Flex your imagination, buttercream be flavored with almost anything.

HO

Rainbow Cake

By Tested and perfected in the Sur la Table kitchen
Ingredients
RAINBOW CAKE
  • Butter for greasing cake pans, at room temperature
  • 5 large eggs, separated, at room temperature
  • 8 ¾ ounces (1 ¼ cups) granulated sugar, divided
  • 6 1/3 ounces cake flour (1 ½ cups), sifted
  • 1 tablespoon baking powder
  • 1 teaspoon fine kosher salt or fine sea salt
  • 4 ounces (½ cup) lukewarm water
  • 4 ounces (½ cup) vegetable oil
  • 2 tablespoons vanilla extract
  • 1/8 teaspoon red, orange, yellow, green, blue and violet gel food colorings
  • ½ cup rainbow sprinkles, for decorating

BUTTERCREAM FROSTING
  • 6 large egg whites, at room temperature
  • 10 ½ ounces (1 ½ cup) granulated sugar
  • 1 ½ pounds (6 sticks) unsalted butter, chilled, cut into 1" pieces
  • ½ tablespoon vanilla bean paste, vanilla extract, or almond extract
  • ½ teaspoon fine kosher salt

Procedure
RAINBOW CAKE For best results, it is best to plan on a 2-day process from start to finish. You will need a minimum of 3, 6" cake pans to make this recipe. If using 3 cake pans, prepare two ½ recipes. Preheat oven to 350°F and position racks in upper and lower thirds of the oven. Butter, flour and line bottom of 6, 6" round cake pans with parchment paper.

To prepare batter: To the bowl of a stand mixer fitted with a whisk attachment add the egg whites. On medium speed, beat whites until foamy. On medium speed, gradually add ½ cup sugar to whipping egg whites. Once all sugar has been added, increase speed to medium-high and beat until soft peaks form. Carefully transfer whites into a clean mixing bowl, do not deflate.

Wipe stand mixer bowl clean. To clean stand mixer bowl fitted with a paddle attachment, add flour, remaining ¾ cup sugar, baking powder and salt. On medium-low speed, add lukewarm water into dry ingredients; increase speed to medium and add oil, egg yolks and vanilla. Beat until mixture is smooth and no streaks remain, scraping down sides of bowl with a silicone spatula as needed. Carefully fold whites into batter in 3 additions, do not deflate batter.

Divide batter evenly between six mixing bowls, each portion will weigh 5 ½ ounces. Add a scant 1/8 teaspoon gel food coloring to each bowl and fold dye throughout batter, do not deflate batter. Adjust vibrancy of color by adding more dye and folding carefully. Pour each colored batter into a prepared cake pan. Using an offset spatula, level top of batter.

Transfer cakes to preheated oven, bake until tester inserted into center comes out clean, 12 to 15 minutes. Cool cakes in pans, 10 minutes. Turn cakes out of pans onto wire cooling racks and cool completely.

Recipe variations: To flavor batter, add 1 teaspoon pure extract such as strawberry, orange or lemon.

BUTTERCREAM FROSTING

Velvety smooth, buttercream is the king of frostings. This version is a Swiss meringue buttercream, which simply means that the egg whites and sugar are heated together before beating. The buttercream can also be flavored in many ways, which makes it very versatile. Any leftover frosting freezes beautifully; it simply needs to be thawed to room temperature and re-whipped to be used another day.

To the bowl of a stand mixer, add egg whites and sugar; whisk to blend. Bring 2 inches of water to a simmer in a medium saucepan. Place bowl with whites and sugar over simmering water and heat, whisking constantly, until mixture reaches 160°F (hot to the touch) on an instant-read thermometer. Remove mixture from heat and attach bowl to a stand mixer fitted with a whisk attachment. Whisk mixture on high speed until it cools to room temperature, is light and billowing, and resembles marshmallow fluff. If mixture is warm, it will melt butter. Test temperature of meringue by touching the bottom exterior of bowl, it should feel room temperature.

Replace whisk attachment with paddle attachment. With mixer on medium-high speed, add chilled butter, a couple of tablespoons at a time, allowing each addition to blend in fully before adding next. Halfway through adding butter, stop mixer and use a silicone spatula to scrape down sides of bowl thoroughly. Continue to whip until all butter has been added and mixture is velvety and smooth. Add vanilla bean paste and salt, whip to incorporate.

Keep buttercream in an airtight container in refrigerator for up to 1 week or in freezer for up to 2 months. Let buttercream come to room temperature and re-whip in the mixer with paddle attachment before using.

Recipe variations: Buttercream can be flavored with melted and cooled chocolate, pureed fruit, natural extracts, toasted nuts, and salted caramel. Flex your imagination, buttercream be flavored with almost anything.

HO