A tender, rich chocolate sponge that’s both moist and fluffy—perfect for layering or enjoying on its own.

Why You’ll Love This Recipe

This cake achieves a delicate crumb through whipped eggs and leaveners, while milk, oil, and a splash of vinegar ensure moistness and a light texture. It’s versatile for layering or frosting and simple to make. scientificallysweet.com+15theguardian.com+15zhangcatherine.com+15allrecipes.com

ingredients

(Tip: You can find the complete list of ingredients and their measurements in the recipe card below.)

8 g baking soda
12 g baking powder
3 g salt
30 g cocoa powder
400 g all-purpose flour
400 g sugar
4 large eggs
250 ml neutral oil (vegetable or canola)
300 ml milk
15 ml white vinegar
1 Tbsp vanilla extract

directions

Preheat oven to 180 °C (350 °F). Line two 16 cm and one 10 cm round pans with parchment.
Combine dry ingredients: sift or whisk flour, cocoa powder, baking powder, baking soda, and salt to ensure even leavening. en.wikipedia.org+7facebook.com+7facebook.com+7bakewithzoha.com+1allrecipes.com+1reddit.com+2scientificallysweet.com+2facebook.com+2
Beat eggs & sugar: In a bowl, beat eggs for 2 minutes, then add sugar and continue beating until the mixture triples in volume—ribbon-like and pale. This aeration is critical for sponge structure. en.wikipedia.org+9facebook.com+9scientificallysweet.com+9
Incorporate oil: Drizzle in the oil and beat for 1 minute.
Add milk mixture: Combine milk with vinegar (which reacts with baking soda to lift the cake), add vanilla, and beat for 2 minutes. bakewithzoha.com+7pastryliving.com+7theguardian.com+7
Fold dry ingredients: Gradually fold in the dry mix using gentle strokes—avoid overmixing to preserve air and prevent tunneling.
Divide and bake: Pour into pans, tap gently to release large bubbles. Bake at 180 °C for about 45 minutes, until a toothpick comes out clean and the cake springs back when touched. zhangcatherine.com
Cool: Let cool 10 minutes in the pan, then transfer to a rack. Rest before slicing or layering.

Servings and timing

Serves: ~10–12 slices, depending on sizing
Prep time: ~15 minutes
Bake time: ~45 minutes
Total time: ~60 minutes

storage/reheating

Room temp: Airtight for up to 3 days.
Fridge: Up to 5 days for best quality.
Freezer: Wrap layers tightly and freeze up to 2 months; thaw in fridge overnight. butternutbakeryblog.comallrecipes.com+13spatuladesserts.com+13zhangcatherine.com+13
Reheat: Gently warm in oven (150 °C for 5–10 min) to refresh moisture.

Variations

Coffee accent: Use hot coffee instead of milk for deeper chocolate flavor.
Dutch cocoa powder: Choose for richer color and flavor. scientificallysweet.com
Buttermilk option: Swap milk + vinegar with buttermilk for extra tang and tender crumb. allrecipes.com+15bakewithzoha.com+15reddit.com+15
Chocolate sponge roll: Bake in sheet pan for roll cakes; fill with whipped cream or ganache.

FAQs

Why use both baking powder and soda?

Soda reacts with vinegar to start leavening and tenderizing, while baking powder provides further lift during baking. zhangcatherine.com+2lacucinaitaliana.com+2cakesbymk.com+2bonappetit.com+3pastryliving.com+3en.wikipedia.org+3

What does vinegar do?

It reacts with baking soda to release CO₂, creating a lighter crumb without imparting flavor.

How do I know when eggs are ready?

Beat until pale and ribbon-like—when lifted, the batter should hold a trail for a few seconds. scientificallysweet.com

How to avoid tunneling?

Sift and mix dry ingredients well and fold gently to prevent large air pockets.

Can I use butter instead of oil?

Oil keeps the cake moist at room temperature; butter-based sponges may stiffen in cool environments. spatuladesserts.com

Can I make a sheet cake?

Yes—bake in a sheet pan for about 30 minutes and cool before layering or rolling.

Why is pan tapping necessary?

Tapping releases trapped air and helps remove large bubbles for even crumb and height.

Oven temperature importance?

Preheat properly and avoid opening the door during baking. Bake time may vary slightly with oven types. en.wikipedia.org+15bhg.com+15scientificallysweet.com+15

What cocoa to use?

Dutch-process gives bold flavor and dark color; natural cocoa offers lighter, fruity notes. Sphere your choice to preference. youtube.com+4hanielas.com+4bakewithzoha.com+4

Is this sponge good for layering?

Absolutely—light enough for delicate whipped fillings or rich fudgy frostings, versatile for many cake styles.

Conclusion

This Moist Chocolate Sponge Cake blends classic sponge techniques with modern tricks—ballooned beaten eggs, milk plus vinegar for tenderness, and oil for lasting moistness. The result is a soft, airy crumb with rich chocolate flavor that performs beautifully as-is or in layered desserts. Enjoy this reliable, delicious cake anytime!