Happy Birthday Cake Slice

Featured in: Warm Baked Goods

This moist vanilla sponge combines softened butter, sugar, and eggs whisked together with flour and baking powder. Baked until golden, it’s sliced into layers filled with creamy buttercream made from unsalted butter, powdered sugar, and vanilla. Finished with vibrant sprinkles, this slice offers a tender crumb and smooth frosting, ideal for festive occasions. Preparation includes careful mixing, baking at 350°F, and delicate layering for a delightful, celebratory dessert.

Updated on Thu, 04 Dec 2025 16:00:00 GMT
A close-up of a beautifully frosted Happy Birthday Cake slice, ready to be enjoyed! Save
A close-up of a beautifully frosted Happy Birthday Cake slice, ready to be enjoyed! | olivedune.com

A festive, moist vanilla sponge cake layered with creamy buttercream and topped with colorful sprinkles—a joyful treat perfect for any celebration.

This cake has always been a highlight at our family celebrations, bringing smiles to everyone’s faces.

Ingredients

  • 1 2/3 cups (210 g) all-purpose flour: For the sponge cake
  • 1 cup (200 g) granulated sugar: For the sponge cake
  • 1/2 cup (115 g) unsalted butter softened: For the sponge cake
  • 3 large eggs at room temperature: For the sponge cake
  • 1/2 cup (120 ml) whole milk: For the sponge cake
  • 2 tsp baking powder: For the sponge cake
  • 1/2 tsp salt: For the sponge cake
  • 1 tbsp pure vanilla extract: For the sponge cake
  • 1 cup (225 g) unsalted butter softened: For the buttercream frosting
  • 3 cups (360 g) powdered sugar sifted: For the buttercream frosting
  • 2 tbsp whole milk: For the buttercream frosting
  • 1 tsp pure vanilla extract: For the buttercream frosting
  • Pinch of salt: For the buttercream frosting
  • 1/4 cup (40 g) colorful sprinkles: For decoration

Instructions

Step 1:
Preheat the oven to 350°F (175°C). Grease and line an 8-inch (20 cm) round cake pan with parchment paper.
Step 2:
In a large bowl, cream together the butter and sugar until light and fluffy, about 3 minutes.
Step 3:
Beat in the eggs, one at a time, mixing well after each addition. Stir in the vanilla extract.
Step 4:
In a separate bowl, whisk together the flour, baking powder, and salt.
Step 5:
Add the dry ingredients to the wet mixture in three parts, alternating with the milk, beginning and ending with the flour. Mix until just combined.
Step 6:
Pour the batter into the prepared cake pan and smooth the top.
Step 7:
Bake for 28-32 minutes, or until a toothpick inserted in the center comes out clean.
Step 8:
Let the cake cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.
Step 9:
For the frosting, beat the butter until creamy. Gradually add powdered sugar, milk, vanilla, and salt, beating until smooth and fluffy.
Step 10:
Once the cake is completely cool, slice it horizontally to create two layers. Spread frosting between the layers and over the top and sides.
Step 11:
Decorate with colorful sprinkles. Slice and serve.
This delicious Happy Birthday Cake slice looks moist, with buttercream and cheerful sprinkles. Save
This delicious Happy Birthday Cake slice looks moist, with buttercream and cheerful sprinkles. | olivedune.com

Gathering around this cake always brings warm family moments and celebrations.

Notes

Pairs well with sparkling wine or fresh lemonade.

Required Tools

8-inch (20 cm) round cake pan, electric mixer, mixing bowls, rubber spatula, wire rack, serrated knife

Allergen Information

Contains eggs, milk, wheat (gluten), and dairy. Check all packaged decorations for potential allergens.

Fluffy vanilla Happy Birthday Cake slice, a celebratory feast, frosted and ready for a bite. Save
Fluffy vanilla Happy Birthday Cake slice, a celebratory feast, frosted and ready for a bite. | olivedune.com

This delightful cake never fails to impress and brightens any occasion.

Cooking Questions & Answers

How do I ensure a moist vanilla sponge?

Use softened butter and room temperature eggs, and avoid over-mixing the batter to keep it tender and moist.

What is the best method to frost the cake layers evenly?

Use a serrated knife to slice the cake evenly, then spread an even layer of buttercream using a rubber spatula for smooth coverage.

Can I add flavors to the buttercream?

Yes, vanilla is traditional, but you can add almond extract or citrus zest to personalize the frosting.

What oven temperature is ideal for baking this sponge?

Preheat the oven to 350°F (175°C) and bake for about 28-32 minutes until a toothpick comes out clean.

How do the colorful sprinkles affect the texture?

They add a light, crunchy contrast on top without changing the soft crumb of the cake slice.

Happy Birthday Cake Slice

Moist vanilla sponge layered with creamy buttercream and topped with colorful sprinkles for celebrations.

Prep Duration
25 min
Time to Cook
30 min
Overall Duration
55 min
Creator: Clara Moretti


Skill Level Medium

Cuisine International

Serves 8 Portions

Dietary Info Vegetarian-Friendly

What You Need

Sponge Cake

01 1 2/3 cups all-purpose flour
02 1 cup granulated sugar
03 1/2 cup unsalted butter, softened
04 3 large eggs, at room temperature
05 1/2 cup whole milk
06 2 teaspoons baking powder
07 1/2 teaspoon salt
08 1 tablespoon pure vanilla extract

Buttercream Frosting

01 1 cup unsalted butter, softened
02 3 cups powdered sugar, sifted
03 2 tablespoons whole milk
04 1 teaspoon pure vanilla extract
05 Pinch of salt

Decoration

01 1/4 cup colorful sprinkles

Steps

Step 01

Prepare Oven and Pan: Preheat the oven to 350°F. Grease and line an 8-inch round cake pan with parchment paper.

Step 02

Cream Butter and Sugar: In a large bowl, cream together the butter and sugar until light and fluffy, approximately 3 minutes.

Step 03

Incorporate Eggs and Vanilla: Beat in the eggs one at a time, mixing well after each addition, then stir in the vanilla extract.

Step 04

Combine Dry Ingredients: Whisk together all-purpose flour, baking powder, and salt in a separate bowl.

Step 05

Mix Batter: Add the dry ingredients to the wet mixture in three parts, alternating with the milk, beginning and ending with the flour, mixing until just combined.

Step 06

Bake the Cake: Pour the batter into the prepared pan, smooth the surface, and bake for 28 to 32 minutes or until a toothpick inserted into the center comes out clean.

Step 07

Cool Cake: Allow the cake to cool in the pan for 10 minutes before transferring onto a wire rack to cool completely.

Step 08

Prepare Frosting: Beat butter until creamy; gradually add powdered sugar, milk, vanilla extract, and salt, beating until smooth and fluffy.

Step 09

Assemble Layers: Once cooled, slice the cake horizontally to create two layers; spread frosting evenly between layers as well as on top and sides.

Step 10

Decorate and Serve: Top with colorful sprinkles, slice into portions, and serve.

Essential Tools

  • 8-inch round cake pan
  • Electric mixer
  • Mixing bowls
  • Rubber spatula
  • Wire rack
  • Serrated knife

Allergy Notice

Always review each component for allergens, and reach out to medical experts if you're uncertain.
  • Contains eggs, milk, wheat (gluten), and dairy.
  • Verify decorations for potential allergens.

Nutrition Breakdown (each portion)

These details are for general advice—please consult your healthcare provider for specific guidance.
  • Energy (kcal): 430
  • Lipids: 21 g
  • Carbohydrates: 57 g
  • Proteins: 4 g