Happy Birthday Cake Slice

Featured in: Simple Sweet Treats

This delight features a soft vanilla sponge made with flour, sugar, eggs, and vanilla extract, baked to perfection. The layers are generously filled with a whipped buttercream blending butter, powdered sugar, vanilla, and milk for smoothness. Finished with a vibrant sprinkle decoration, it offers a moist, flavorful experience ideal for celebrations. Preparation involves creaming, folding, baking, cooling, frosting, and decorating to create an inviting presentation that combines texture and sweetness in every bite.

Updated on Thu, 04 Dec 2025 14:27:00 GMT
A slice of Happy Birthday Cake shows a fluffy vanilla sponge frosted with buttercream and sprinkles. Save to Pinterest
A slice of Happy Birthday Cake shows a fluffy vanilla sponge frosted with buttercream and sprinkles. | citrushearth.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 been a hit at every birthday party I have brought it to, always earning compliments for its light texture and vibrant appearance.

Ingredients

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

Instructions

Preheat Oven:
Preheat the oven to 350°F (175°C). Grease and line an 8-inch (20 cm) round cake pan with parchment paper.
Cream Butter and Sugar:
In a large bowl cream together the butter and sugar until light and fluffy about 3 minutes.
Add Eggs and Vanilla:
Beat in the eggs one at a time mixing well after each addition. Stir in the vanilla extract.
Mix Dry Ingredients:
In a separate bowl whisk together the flour baking powder and salt.
Combine Mixtures:
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.
Pour Batter:
Pour the batter into the prepared cake pan and smooth the top.
Bake:
Bake for 28-32 minutes or until a toothpick inserted in the center comes out clean.
Cool Cake:
Let the cake cool in the pan for 10 minutes then turn out onto a wire rack to cool completely.
Prepare Frosting:
For the frosting beat the butter until creamy. Gradually add powdered sugar milk vanilla and salt beating until smooth and fluffy.
Assemble Cake:
Once the cake is completely cool slice it horizontally to create two layers. Spread frosting between the layers and over the top and sides.
Decorate:
Decorate with colorful sprinkles. Slice and serve.
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| citrushearth.com

Sharing this cake at family birthdays always fills our home with joy and celebration, creating wonderful memories.

Notes

For a chocolate variation replace 1/3 cup (40 g) of flour with unsweetened cocoa powder. Add a layer of fruit jam for extra flavor. 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.

Moist Happy Birthday Cake slice with creamy frosting and colorful sprinkles, perfect for birthdays and celebrations. Save to Pinterest
Moist Happy Birthday Cake slice with creamy frosting and colorful sprinkles, perfect for birthdays and celebrations. | citrushearth.com

This birthday cake is sure to impress your guests and make any celebration extra special.

Recipe FAQs

What makes the sponge moist and fluffy?

The combination of butter, eggs, and milk along with proper creaming of sugar and butter helps achieve a moist, tender texture.

How do I prevent the sponge from drying out during baking?

Bake at the recommended temperature and test doneness with a toothpick to avoid overbaking. Cooling in the pan briefly helps retain moisture.

What is the best way to achieve smooth buttercream frosting?

Beat softened butter until creamy before gradually adding powdered sugar, milk, vanilla, and a pinch of salt for a fluffy, smooth consistency.

Can I add flavors to the sponge or frosting?

Yes, vanilla extract is used here, but you can incorporate cocoa powder, fruit jams, or extracts to customize flavor profiles.

How should the layers be assembled for best results?

Once the sponge is fully cooled, slice horizontally, spread buttercream evenly between layers, then cover the top and sides before decorating.

What decorations complement this cake slice?

Colorful sprinkles add festive appeal, but nuts, fruit pieces, or edible glitter can also enhance the visual and flavor profile.

Happy Birthday Cake Slice

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

Prep duration
25 minutes
Time to cook
30 minutes
Overall time
55 minutes
Created by Elise Porter


Skill level Medium

Cuisine Type International

Makes 8 Number of servings

Dietary details Meat-Free

What Goes In

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, 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

How to Make It

Step 01

Prepare the Oven and Pan: Preheat 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, beat unsalted butter and granulated sugar together until light and fluffy, approximately 3 minutes.

Step 03

Incorporate Eggs and Vanilla: Add eggs one at a time, mixing thoroughly after each addition. Stir in pure vanilla extract.

Step 04

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

Step 05

Mix Batter: Alternate adding dry ingredients and whole milk into the wet mixture in three parts, starting and ending with flour. Stir until just combined.

Step 06

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

Step 07

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

Step 08

Prepare the Frosting: Beat unsalted butter until creamy. Gradually incorporate powdered sugar, whole milk, vanilla extract, and a pinch of salt, mixing until smooth and fluffy.

Step 09

Assemble Layers: Slice cooled cake horizontally into two layers. Spread frosting evenly between layers, then cover top and sides with remaining frosting.

Step 10

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

What You’ll Need

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

Allergy details

Double-check ingredients for allergens; talk with your doctor if you’re uncertain.
  • Contains eggs, milk, wheat (gluten), and dairy. Verify allergen information on decorations.

Nutrition info (for each serving)

Nutrition data is for reference and isn’t meant as health advice.
  • Calorie count: 430
  • Fat content: 21 grams
  • Carbohydrates: 57 grams
  • Protein amount: 4 grams