Equipment
Ingredients
Fatless Chocolate Sponge
- 4 large eggs, room temperature
- 100 g caster sugar
- 80 g cake flour
- 25 g dutch-process cocoa powder
- 5 ml vanilla extract
Raspberry Compote & Drizzle
- 300 g fresh raspberries
- 40 g granulated sugar
- 10 ml lemon juice
- 15 ml water
Garnish
- 5 g icing sugar
- 8 fresh raspberries
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 173 kcal
- Protein
- 5 g
- Carbohydrates
- 33 g
- Fat
- 3 g
- Fiber
- 4 g
- Sugar
- 20 g
- Sodium
- 37 mg
- Saturated Fat
- 1 g
- Trans Fat
- 0 g
- Monounsaturated Fat
- 1 g
- Polyunsaturated Fat
- 1 g
- Cholesterol
- 93 mg
- Potassium
- 156 mg
- Calcium
- 30 mg
- Iron
- 1.3 mg
- Magnesium
- 30 mg
- Phosphorus
- 95 mg
- Zinc
- 0.8 mg
- Vitamin A
- 41 mcg
- Vitamin C
- 11 mg
- Vitamin D
- 0.5 mcg
- Vitamin E
- 0.6 mg
- Vitamin K
- 3 mcg
- Vitamin B6
- 0.1 mg
- Vitamin B12
- 0.2 mcg
- Thiamin
- 0.04 mg
- Riboflavin
- 0.15 mg
- Niacin
- 0.5 mg
- Folate
- 24 mcg
- Water
- 58 g
- Alcohol
- 0 g
- Caffeine
- 7 mg
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat your oven to 170°C/340°F. Line the bottom of a 20cm round cake tin with parchment paper. Do not grease the sides of the tin; the batter needs to grip the sides to rise properly.
Sift the cake flour and cocoa powder together three times. This aerates the dry ingredients to prevent clumps from deflating the egg foam later.
Combine eggs, caster sugar, and vanilla in a large heatproof bowl set over a pan of simmering water (bain-marie). Whisk constantly until the sugar dissolves and the mixture is warm to the touch (about 40°C/105°F).
Remove from heat and whisk on high speed using an electric mixer until the mixture has tripled in volume, is pale, and reaches the 'ribbon stage' (where a trail of batter stays on the surface for a few seconds before sinking). This takes about 5-7 minutes.
Gently fold the sifted flour and cocoa into the egg foam in three batches. Use a metal spoon or spatula to cut down the center and fold over the top. Be extremely gentle to retain the air bubbles.
Pour the batter into the prepared tin and bake immediately for 20-25 minutes. The cake is done when the top springs back when lightly pressed and the sides pull away slightly from the tin.
While the cake bakes, combine raspberries, granulated sugar, lemon juice, and water in a small saucepan. Simmer over medium heat until the fruit breaks down and the sauce thickens slightly, about 10 minutes. Strain half for a smooth drizzle, keep the other half chunky for filling. Let cool completely.
Once the cake is cool, remove from the tin. Slice horizontally into two layers. Spread the chunky raspberry compote in the middle. Top with the second sponge layer.
Dust the top with icing sugar and drizzle with the smooth raspberry coulis. Garnish with fresh raspberries before serving.
Chef's Notes
- Warming the eggs and sugar before whisking helps dissolve the sugar and relaxes the egg proteins, allowing them to whip to a greater volume.
- Because there is no fat (butter or oil) in the sponge, this cake is best eaten on the day it is made. It relies on the moisture from the filling to stay palatable.
- If using frozen raspberries for the compote, you may need to simmer for an extra 2-3 minutes to evaporate the excess water content.
- Dutch-process cocoa is essential here; natural cocoa is more acidic and can react with the egg foam structure unpredictably in this specific chemical-leavener-free formula.
Storage
Refrigerator: 2 days — Store in an airtight container to prevent drying out.
Freezer: 1 month — Freeze sponge layers without filling only.
Troubleshooting
The cake collapsed or turned out dense and rubbery
Cause: The air was knocked out of the eggs during the folding stage, or the dry ingredients were not folded in gently enough.
Fix: Cannot be fixed. Use dense cake pieces for a trifle.
Prevention: Fold using a 'cut and turn' motion and stop exactly when no flour streaks remain.
Cultural Context
This recipe is a variation of the 'Genoise' sponge, a fundamental building block of French pâtisserie named after the city of Genoa. While traditional Genoise often contains melted butter, this fatless version (Biscuit de Savoie style) was historically favored for its lightness and ability to soak up syrups and liqueurs without becoming heavy.
