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–+ servings
Fluffy Birthday Sponge

Fluffy Birthday Sponge

Bake the perfect Fluffy Birthday Sponge! Our easy, one-bowl chocolate cake recipe yields a moist, rich dessert ideal for any celebration.
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Prep Time 25 minutes
Cook Time 35 minutes
Cooling Time 1 hour
Total Time 2 hours
Servings: 12 people
Calories: 498
Ingredients Equipment Method Nutrition Notes

Ingredients
  

  • 1 3/4 cups all-purpose flour
  • 2 cups granulated sugar
  • 3/4 cup cocoa powder (natural, unsweetened)
  • 2 tsp baking soda
  • 1 tsp baking powder
  • 1 tsp salt
  • 1 cup buttermilk or half-and-half
  • 1/2 cup vegetable oil
  • 2 large eggs, at room temperature
  • 1 tsp vanilla extract
  • 1 cup hot coffee freshly brewed or instant
  • 6 ounces semisweet chocolate, chopped for frosting
  • 1 cup unsalted butter, room temperature for frosting
  • 3 cups powdered sugar, sifted for frosting
  • 1 pinch salt for frosting
  • 1 tsp vanilla extract for frosting
  • 1/2 cup sour cream for frosting

Equipment

  • Large Mixing Bowl
  • Whisk
  • Spatula
  • Two 8-inch Round Cake Pans
  • Parchment Paper

Method
 

  1. Preheat your oven to 350°F (175°C). Grease two 8-inch round cake pans with butter or baking spray and line the bottoms with parchment paper.
  2. In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt for about 30 seconds.
  3. In a smaller bowl, whisk the buttermilk, vegetable oil, eggs, and vanilla until smooth.
  4. Pour the wet ingredients into the dry ingredients and mix gently until just combined. Add the hot coffee and mix until the batter is thin and well combined.
  5. Divide the batter evenly between the prepared pans. Bake for 35-40 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
  6. After baking, let the cakes cool in the pans for at least 15 minutes. Then, run a knife around the edges, invert them onto a wire rack to cool completely, and remove the parchment paper.
  7. For the frosting, melt the chopped chocolate and allow it to cool slightly. In a stand mixer, beat the butter until pale and fluffy, then gradually mix in the powdered sugar, pinch of salt, and vanilla until smooth.
  8. Stir in the cooled chocolate with the sour cream. Mix until silky and creamy.
  9. Place one layer of cake on a serving plate and spread frosting over it. Add the second layer and apply a crumb coat. Chill for 15 minutes, then frost with the remaining frosting.

Nutrition

Calories: 498kcalCarbohydrates: 65gProtein: 5gFat: 25gSaturated Fat: 15gPolyunsaturated Fat: 1gMonounsaturated Fat: 6gCholesterol: 85mgSodium: 250mgPotassium: 210mgFiber: 3gSugar: 45gVitamin A: 600IUCalcium: 50mgIron: 2.5mg

Notes

To ensure the best results, use room-temperature ingredients, and avoid overmixing to keep the cake fluffy.
If you don’t have buttermilk, mix 1 tablespoon of lemon juice or white vinegar with 1 cup of milk and let it sit for 5 minutes.
Variations include gluten-free, vegan, and flavor additions like peppermint or orange zest.
Cakes can be stored at room temperature for up to 3 days in an airtight carrier, or refrigerated for up to 5 days. For longer storage, freeze the unfrosted layers for up to 3 months.
For a smooth frosting finish, use a crumb coat technique by spreading a thin layer of frosting first, then chilling before adding the final layer.
Tried this recipe?Let us know how it was!