Pinterest Image is the tall, rainbow-layered vanilla cake that stops the scroll every time you see it. Six thin, tender sponge layers stack up with whipped vanilla buttercream between each one, then get a smooth crumb coat so the colors glow through the frosting.
The trick is baking the layers thin and fast so they stay moist instead of drying out, then chilling the cake before the final coat. That cold-set buttercream is what gives you those razor-sharp slices in every photo.
Whether you are baking for a birthday, a gender reveal, or just because the colors make you happy, this cake is built to look as good as it tastes. Follow the temperatures and cues below and you will get bakery-level layers at home.
Why You'll Love This Recipe
About the Ingredients
3 cups (360g) all-purpose flour
Spoon and level the flour so you do not pack it in. For a slightly lighter crumb, swap 1/2 cup for cake flour.
2 1/2 teaspoons baking powder
Check the date on your tin, since old baking powder will not lift thin layers. Aluminum-free brands taste cleaner here.
1/2 teaspoon fine salt
Fine sea salt dissolves evenly into the batter. If using table salt, reduce to 1/4 teaspoon.
1 cup (2 sticks / 227g) unsalted butter, room temperature
Butter should dent when pressed but not feel greasy. Salted butter works if you cut the added salt to 1/4 teaspoon.
2 cups (400g) granulated sugar
Superfine sugar creams faster and finer. Do not reduce the sugar, as it keeps the thin layers tender and moist.
4 large eggs, room temperature
Room-temperature eggs emulsify better and add volume. Submerge cold eggs in warm water for 10 minutes if needed.
1 tablespoon vanilla extract
Use pure, not imitation, for a clean bakery flavor. Vanilla bean paste adds lovely flecks.
1 1/4 cups (300ml) whole milk, room temperature
Whole milk gives richness; 2% works fine. Warm it slightly so it does not seize the butter.
Gel food coloring in red, orange, yellow, green, blue, and purple
Gel or paste colors keep the batter from thinning. Liquid dye needs far more and can make layers gummy.
1 1/2 cups (3 sticks / 340g) unsalted butter, room temperature, for frosting
This is for the buttercream. European-style butter holds shape better in warm kitchens.
5 cups (600g) powdered sugar, sifted
Sifting removes lumps so the frosting pipes smoothly. Cornstarch-free brands taste less chalky.
3 tablespoons heavy cream, plus more as needed
Heavy cream loosens the frosting without thinning the flavor. Whole milk works in a pinch.
Tips & Tricks
Weigh Your Batter
Divide batter with a scale so all six layers bake to the same thickness and finish at the same time.
Do Not Overbake
Thin layers go from done to dry in about 60 seconds, so pull them the moment the center springs back.
Chill Before Crumb Coat
A 30-minute chill firms the layers so the frosting does not drag crumbs into the final coat.
Keep Frosting Cool
If the buttercream looks soupy, chill the bowl for 10 minutes and rewhip instead of adding more sugar.
Pro Tips
Step-by-Step Instructions
1. Prep pans and oven
Heat the oven to 350F (175C). Grease six 8-inch round pans, line the bottoms with parchment, and grease the parchment. If you own fewer pans, bake the layers in batches and let the pans cool between uses.
2. Cream butter and sugar
Beat the 1 cup butter and 2 cups sugar on medium-high for 3 to 4 minutes until pale and fluffy, scraping the bowl once. You are looking for a visibly lighter color and a soft, airy texture.
3. Add eggs and vanilla
Beat in the eggs one at a time, fully mixing each before adding the next, then stir in the vanilla. The batter should look glossy and smooth, not curdled.
4. Alternate dry and milk
Whisk the flour, baking powder, and salt in a bowl. Add it to the butter mixture in three additions, alternating with the milk in two, starting and ending with the dry. Mix on low just until streaks disappear.
5. Color the batter
Divide the batter evenly among six bowls, about 1 cup each. Tint each bowl red, orange, yellow, green, blue, and purple with gel color, stirring until the shade is even.
6. Bake the layers
Pour each color into a prepared pan and bake at 350F (175C) for 12 to 14 minutes, until the center springs back and a toothpick comes out clean. Edges should look set and barely golden, never browned.
7. Cool and level
Cool the layers in the pans for 5 minutes, then turn out onto racks to cool completely, about 30 minutes. Press any domed tops flat while still warm.
8. Make the buttercream
Beat the 1 1/2 cups butter for 2 minutes until creamy. Add the sifted powdered sugar one cup at a time on low, then beat in the cream and a pinch of salt for 3 minutes until fluffy and spreadable.
9. Stack and crumb coat
Place the purple layer on a board, spread about 1/3 cup frosting, and repeat up the rainbow ending with red on top. Cover the whole cake with a thin crumb coat and chill 30 minutes.
10. Finish and serve
Apply a thick final coat of buttercream, smooth the sides with a warm scraper, and chill 1 hour. Slice with a hot, dry knife for clean rainbow edges.
Delicious Variations
Chocolate Rainbow
Replace 1/2 cup flour with cocoa and add 1/4 cup extra milk for a rich chocolate version.
Fruity Twist
Fold 1 teaspoon raspberry or lemon extract into the buttercream for a brighter finish.
Naked Cake Style
Skip the final coat and leave the crumb coat exposed for a rustic, trendy look.
How to Store Pinterest Image
Refrigerator
Store covered in the fridge for up to 4 days; let it sit at room temperature 30 minutes before serving so the buttercream softens.
Freezer
Wrap unfrosted layers tightly in plastic and foil and freeze up to 2 months; thaw overnight in the fridge before stacking.
Reheating
No reheating needed; a 10-second microwave pulse per slice softens chilled cake if you prefer it warm.
Frequently Asked Questions
Q: How do I keep rainbow cake layers from drying out?
Bake them thin and fast, then cool and wrap them while barely warm. Overbaking by even a minute is the main cause of dry layers, so pull them as soon as the center springs back.
Q: Can I make this Pinterest image cake ahead of time?
Yes, you can bake and freeze the layers up to 2 months ahead and make the buttercream 3 days ahead. Assemble and frost the day before serving for the best texture.
Q: Why did my buttercream turn soupy?
Warm butter is almost always the culprit, so chill the bowl for 10 minutes and rewhip. Adding more sugar only makes it grainy, so fix the temperature first.
Q: How many people does this cake serve?
This recipe serves 6 generously as written, with tall slices. For a crowd, cut thinner slices and it comfortably stretches to 10 to 12.
Q: Do I need six separate cake pans?
No, you can bake in batches with two or three pans. Just let the pans cool completely and re-grease before each new batch so the layers release cleanly.
Bake this Pinterest Image cake for your next celebration and watch everyone reach for a second slice. Snap a photo of your rainbow layers and tag me so I can see your gorgeous creation.
Pinterest Image
Pinterest Image is a show-stopping rainbow layer cake with silky vanilla buttercream that bakes up moist and slices cleanly every single time.
🧂 Ingredients
- 3 cups (360g) all-purpose flour
- 2 1/2 teaspoons baking powder
- 1/2 teaspoon fine salt
- 1 cup (2 sticks / 227g) unsalted butter, room temperature
- 2 cups (400g) granulated sugar
- 4 large eggs, room temperature
- 1 tablespoon vanilla extract
- 1 1/4 cups (300ml) whole milk, room temperature
- Gel food coloring in red, orange, yellow, green, blue, and purple
- 1 1/2 cups (3 sticks / 340g) unsalted butter, room temperature, for frosting
- 5 cups (600g) powdered sugar, sifted
- 3 tablespoons heavy cream, plus more as needed
📋 Instructions
- 1Prep pans and oven — Heat the oven to 350F (175C). Grease six 8-inch round pans, line the bottoms with parchment, and grease the parchment. If you own fewer pans, bake the layers in batches and let the pans cool between uses.
- 2Cream butter and sugar — Beat the 1 cup butter and 2 cups sugar on medium-high for 3 to 4 minutes until pale and fluffy, scraping the bowl once. You are looking for a visibly lighter color and a soft, airy texture.
- 3Add eggs and vanilla — Beat in the eggs one at a time, fully mixing each before adding the next, then stir in the vanilla. The batter should look glossy and smooth, not curdled.
- 4Alternate dry and milk — Whisk the flour, baking powder, and salt in a bowl. Add it to the butter mixture in three additions, alternating with the milk in two, starting and ending with the dry. Mix on low just until streaks disappear.
- 5Color the batter — Divide the batter evenly among six bowls, about 1 cup each. Tint each bowl red, orange, yellow, green, blue, and purple with gel color, stirring until the shade is even.
- 6Bake the layers — Pour each color into a prepared pan and bake at 350F (175C) for 12 to 14 minutes, until the center springs back and a toothpick comes out clean. Edges should look set and barely golden, never browned.
- 7Cool and level — Cool the layers in the pans for 5 minutes, then turn out onto racks to cool completely, about 30 minutes. Press any domed tops flat while still warm.
- 8Make the buttercream — Beat the 1 1/2 cups butter for 2 minutes until creamy. Add the sifted powdered sugar one cup at a time on low, then beat in the cream and a pinch of salt for 3 minutes until fluffy and spreadable.
- 9Stack and crumb coat — Place the purple layer on a board, spread about 1/3 cup frosting, and repeat up the rainbow ending with red on top. Cover the whole cake with a thin crumb coat and chill 30 minutes.
- 10Finish and serve — Apply a thick final coat of buttercream, smooth the sides with a warm scraper, and chill 1 hour. Slice with a hot, dry knife for clean rainbow edges.
