This Rainbow Vertical Cake recipe is a stunning and colorful recipe, which is made with a light sponge cake and silky Swiss meringue buttercream. It’s the perfect birthday centerpiece, ready in about 3.5 hours.
Jump to RecipeRainbow Vertical Cake Ingredients
A colorful creation from scratch.
For the Cake:
- Baking spray, for the pans
- All-purpose flour, for dusting
- 8 large eggs, separated
- 1 cup granulated sugar, separated
- 2 tablespoons vanilla extract
- 1 ¾ cups cake flour
- ½ teaspoon kosher salt
- ¼ cup confectioners’ sugar, for dusting
For the Swiss Meringue Buttercream:
- 2 ¼ cup granulated sugar
- 2 tablespoons freshly squeezed lemon juice
- Pinch of kosher salt
- 12 large egg whites
- 9 sticks (4 ½ cups) unsalted butter, cut into chunks, at room temperature
- 2 tablespoons vanilla extract
- Red, orange, yellow, green, blue, and purple gel food color
How To Make a Rainbow Vertical Cake
Building the stripes from the inside out.
- Prep the Oven and Pans: Arrange an oven rack in the middle of the oven and preheat to 350°F. Spray two 18-by-13-inch half-sheet pans with baking spray, line with parchment, spray the parchment, and then dust with flour, tapping out any excess.
- Make the Cake Batter: In a medium bowl, whip the egg yolks with ½ cup of the granulated sugar and vanilla on medium-high speed until thick ribbons form, about 5 minutes. In a separate large, clean bowl, whip the egg whites and salt on medium-high speed until foamy. With the mixer running, slowly add the remaining ½ cup granulated sugar and beat until glossy, stiff peaks form, about 5 minutes.
- Combine the Batter: Using a large spatula, gently fold the egg whites into the yolk mixture. Sift in the flour in four additions, folding gently after each addition until just combined. Be careful not to deflate the batter.
- Bake and Roll the Cakes: Divide the batter evenly between the two prepared pans and spread into a thin layer. Bake for about 12 minutes, until lightly springy to the touch. Immediately dust two large, clean kitchen towels with confectioners’ sugar. Flip the warm cakes out onto the towels, peel off the parchment paper, and gently roll up each cake with the towel from the short end. Set aside to cool completely.
- Prepare the Buttercream Base: In the heatproof bowl of a stand mixer, whisk the granulated sugar, lemon juice, salt, and egg whites by hand. Set the bowl over a saucepan of simmering water (creating a double boiler) and whisk constantly until the mixture is warm and the sugar has completely dissolved.
- Whip the Meringue: Transfer the bowl to the stand mixer fitted with the whisk attachment. Beat on medium-high speed for 10 to 15 minutes, until the meringue is cool to the touch and holds stiff, glossy peaks.
- Finish the Buttercream: With the mixer still running, add the room-temperature butter, a few chunks at a time. The mixture will deflate and may look curdled—this is normal. Keep beating on medium-high speed until it comes back together into a smooth, silky buttercream, about 5 more minutes. Beat in the vanilla.
- Color the Frosting: Divide about 4 ½ cups of the frosting evenly among six small bowls. Tint each bowl with red, orange, yellow, green, blue, and purple gel food coloring. Transfer each color to a separate piping bag. Cover and reserve the remaining white frosting.
- Pipe the Rainbow Stripes: Carefully unroll the cooled cake layers. Cut each cake in half lengthwise to create four long strips. On each of the four cake strips, pipe even, lengthwise lines of the colored frosting, starting with red and following the order of the rainbow.
- Roll and Assemble the Cake: Take one frosted cake strip and roll it into a tight spiral. Place it on its end in the center of a cake platter. Take the next strip and wrap it around the first spiral, continuing the roll. Repeat with the remaining two strips to create one large, coiled cake. Chill in the refrigerator for 30 minutes to firm up.
- Apply the Crumb Coat: Trim the top and bottom of the cake so they are flat. Place the cake upright on a platter. Spread a thin layer of the reserved white frosting over the top and sides to trap any crumbs. Chill for another 30 minutes.
- Frost and Decorate: Cover the cake with the remaining white frosting, using an offset spatula to create swirls or a smooth finish as desired.
Recipe Tips
- Why did my buttercream break or curdle? This is the #1 problem with Swiss Meringue Buttercream! It’s almost always a temperature issue. If the meringue is too warm, the butter will melt. If the butter is too cold, it won’t combine. The solution is almost always to just keep whipping. Keep the mixer on high, and it will come together.
- How do I keep my sponge cake from cracking? The recipe instructs you to roll the cakes in a towel while they are warm. This “trains” the cake to be in a rolled shape, so it won’t crack when you unroll and re-roll it with the frosting.
- How do I get a light, airy sponge? Beating the egg whites to stiff, glossy peaks is key. But just as important is how you fold. Be very gentle, using a large spatula to cut down the middle and bring the batter up and over. Do not stir, or you will deflate all the air.
- Can I make this in stages? Yes, this is an advanced cake and is best made in stages. Day 1: Bake the cake layers, roll them in towels, let them cool, then wrap them in plastic. Day 2: Make the buttercream, assemble the cake, and chill it.
What To Serve With Rainbow Vertical Cake
This cake is a stunning centerpiece and a complete dessert. It needs nothing else!
- A hot cup of black coffee or tea
- A glass of milk
- A glass of Champagne to celebrate
How To Store Rainbow Vertical Cake
- Refrigerate: Because the frosting is made with butter and egg whites, this cake must be stored in the refrigerator. Keep it in a tall cake carrier or cover it lightly. It will last for up to 4 days.
- Serve: This cake tastes much better at room temperature. Let it sit out for 1-2 hours before serving to allow the buttercream and cake to soften.
Rainbow Vertical Cake Nutrition Facts
(Per slice, assuming 20 slices)
- Calories: ~780 kcal
- Total Fat: 55g
- Saturated Fat: 33g
- Cholesterol: 290mg
- Sodium: 310mg
- Total Carbohydrate: 65g
- Dietary Fiber: 1g
- Sugars: 50g
- Protein: 8g
Nutrition information is estimated and may vary based on ingredients and cooking methods used.
FAQs
What is a “vertical cake”?
Unlike a traditional layer cake, which has horizontal stripes, a vertical cake is made by wrapping long, frosted strips of cake into a spiral. When you cut a slice, you reveal beautiful vertical stripes.
What if I don’t have cake flour?
For this delicate sponge, cake flour is highly recommended. To make a substitute: measure 1 ¾ cups of all-purpose flour, remove 3.5 tablespoons of it, and replace that with 3.5 tablespoons of cornstarch. Sift this mixture very well.
Can I use a cake mix?
It is not recommended. A box cake mix is usually too crumbly and not flexible enough to be rolled without cracking.
Rainbow Vertical Cake Recipe
Course: DessertCuisine: AmericanDifficulty: EasyServings
20
servingsPrep time
1
hour30
minutesCooking time
25
minutesCalories
780
kcalA stunning show-stopper cake with surprising vertical rainbow stripes on the inside, all wrapped in a silky Swiss meringue buttercream.
Ingredients
[Full ingredients from all sections]
Directions
- Preheat oven to 350°F. Prep two 18×13-inch pans (grease, parchment, spray, flour).
- Sponge Cake: Beat 8 egg yolks with 1/2 cup sugar and vanilla until thick.
- In a clean bowl, beat 8 egg whites and salt until foamy. Slowly add 1/2 cup sugar and beat to stiff, glossy peaks.
- Gently fold the whites into the yolk mixture. Sift and fold in the cake flour.
- Spread batter evenly between the two pans. Bake for ~12 minutes.
- Immediately invert the hot cakes onto towels dusted with confectioners’ sugar. Peel parchment. Roll the cakes up (with the towels) and let cool completely.
- Buttercream: Whisk 12 egg whites, 2 1/4 cups sugar, lemon juice, and salt over a double boiler until sugar dissolves.
- Transfer to a mixer and whip on high for 10-15 minutes until stiff, glossy, and completely cool.
- On low speed, add the room-temp butter, one piece at a time. Once all butter is in, beat on high until smooth. (It will curdle, just keep beating). Add vanilla.
- Assemble: Divide 4.5 cups of frosting into 6 bowls and tint them with the rainbow colors.
- Unroll the cooled cakes. Cut them in half lengthwise to create 4 strips.
- Pipe the 6 colored frostings in long, lengthwise stripes onto each of the 4 cake strips.
- Roll one strip into a tight spiral. Wrap the next strip around it, continuing the spiral. Repeat.
- Chill the large rolled cake for 30 min. Crumb coat with white frosting. Chill 30 min.
- Frost the entire cake with the remaining white frosting.
Notes
- This is an advanced cake. Be patient, especially with the buttercream.
- Roll the cakes while they are hot to prevent them from cracking.
- If the buttercream curdles, just keep beating on high speed. It will come together.
- Store the finished cake in the refrigerator but serve at room temperature.
