Description

A dreamy, pastel-hued layer cake swirled and crowned with fluffy cotton candy “clouds.” Light as air vanilla sponge layers are filled with marshmallow-flavored buttercream, then frosted in a soft ombré of pink and blue. Perfect for birthdays, baby showers, or anytime you want a showstopper that tastes as sweet as it looks!

Ingredients

Scale

For the vanilla sponge:

2½ cups (312 g) all-purpose flour
2½ tsp baking powder
½ tsp salt
1 cup (226 g) unsalted butter, room temperature
2 cups (400 g) granulated sugar
4 large eggs, room temperature
1 Tbsp pure vanilla extract
1 cup (240 ml) whole milk, room temperature
Pastel gel food coloring in pink and blue

For the cotton-candy buttercream:

1½ cups (340 g) unsalted butter, room temperature
6 cups (720 g) powdered sugar, sifted
2 Tbsp marshmallow fluff
½ tsp pure vanilla extract
2–3 Tbsp heavy cream (as needed for consistency)

For assembly & decoration:

2–3 large tufts of cotton candy (pink and blue)
Edible glitter or pearl dust (optional)
Sprinkles or sugar pearls (optional)

Instructions

1️⃣ Bake the sponge layers.

Preheat oven to 350 °F (175 °C). Grease and line three 8″ round cake pans.
Whisk together flour, baking powder, and salt; set aside.
In a large bowl, cream butter and sugar on medium speed until pale and fluffy, about 4 minutes.
Add eggs one at a time, beating well after each, then stir in vanilla.
With mixer on low, alternate adding flour mixture and milk in three batches (flour first), mixing just until combined.

2️⃣ Color the batter.

Divide batter equally into three bowls. Leave one uncolored, tint one with a few drops of pink gel, and one with blue gel—each just until pastel.

3️⃣ Fill and bake.

Spread each color into its own pan, smoothing tops.
Bake 18–22 minutes, or until a toothpick inserted in the center comes out clean.
Cool in pans 10 minutes, then invert onto wire racks to cool completely.

4️⃣ Make the buttercream.

In a large bowl, beat butter on medium until creamy (about 2 minutes).
Gradually add powdered sugar, one cup at a time, scraping sides as needed.
Beat in marshmallow fluff and vanilla, then add heavy cream a tablespoon at a time until frosting is light and spreadable.

5️⃣ Assemble the cake.

Place the uncolored (white) layer on your cake stand. Pipe or spread a thin layer of buttercream.
Top with the pink layer, repeat frosting, then finish with the blue layer.

6️⃣ Crumb coat and chill.

Apply a thin “crumb coat” of buttercream around the sides and top.
Chill 20 minutes to set.

7️⃣ Final frosting & ombré effect.

Divide remaining buttercream into three bowls: leave one white, tint one pink, one blue (light pastels).
Starting at the bottom edge, apply a stripe of blue, then white in the middle, then pink at the top.
Use an offset spatula or bench scraper to smooth and blend the stripes upward into a soft ombré.

8️⃣ Decorate with cotton candy.

Gently nestle tufts of cotton candy on top of the cake, arranging to look like candy clouds.
Sprinkle edible glitter or sugar pearls around the edges for extra whimsy.

9️⃣ Serve immediately.

Cotton candy will begin to melt if left out—add right before guests arrive for maximum effect!

Notes

Stabilizing cotton candy: For longer display, tuck small picks into the cake layers first, then gently attach candy tufts so they don’t rest on the frosting directly.
Flavor twists: Swap half the vanilla extract in the buttercream for cotton-candy or almond flavoring.
Make-ahead: Bake layers up to 2 days ahead; wrap tightly in plastic and refrigerate. Bring to room temp before assembling.
Vegan/dairy-free option: Use plant-based butter, plant milk, and dairy-free marshmallow fluff.
Extra shine: Lightly dust the frosted cake with pearl dust for an ethereal shimmer.

Prep Time: 30 min
Cook Time: 20 min