This chocolate sponge has been my go-to for celebrations and quiet Sunday teas alike. I first perfected this approach on a rainy afternoon when I wanted a cake that felt feather-light yet deeply chocolatey — a cake that wouldn’t weigh down the palate. What makes it special is the balance: a delicate crumb from whipped eggs and just enough cocoa to sing through the crumb, paired with a bright raspberry filling and silky chocolate whipped cream that brings everything together.

I remember the first time I served this at a small family gathering; everyone asked whether it was from a bakery. The layers stayed pillowy soft even the next day, thanks to a small but crucial step: brushing the sponge with a simple syrup. Because the sponge is low in fat, a touch of syrup keeps it tender without making it soggy. If you love classic Victorian-style sponges with a modern chocolate twist, this will quickly become a favorite.

Ingredients

• Sponge Cake: This recipe uses separated eggs whipped to create lift. Look for large eggs at room temperature and use regular all-purpose flour — cake flour won’t behave the same here because we rely on the combination of flour and cornstarch for a tender crumb.
• Cornstarch: Acts like a partial substitution for cake flour by reducing gluten formation; measure by spooning into the cup to avoid compaction.
• Cocoa powder: Choose a high-quality unsweetened cocoa like Dutch-process or natural to control bitterness; I prefer a mid-strength cocoa so the jam and cream can still shine.
• Instant coffee powder: A tiny amount enhances chocolate flavor without adding coffee taste — do not use brewed coffee here.
• Sugar: Divided sugar ensures stability in both whipped whites and yolk mixture; use fine granulated for quickest dissolution.
• Oil: Neutral vegetable oil (canola) keeps the crumb moist without changing flavor; melted butter will firm up and change texture.

Instructions

Prepare and Preheat:Preheat the oven to 320°F (160°C) fan. Line the bottoms of two 8 x 3 inch cake tins with parchment paper and leave the sides ungreased so batter can cling and rise properly. If your oven has no fan setting, set to 347°F (175°C).Combine Dry Ingredients:In a bowl whisk together 2 tablespoons all-purpose flour, 1/3 cup cornstarch, 1/4 teaspoon baking powder, 2 tablespoons unsweetened cocoa, 1 teaspoon instant coffee powder, and 1/4 teaspoon salt until evenly distributed. No need to sift yet; folding later will minimize overworking.Whip Egg Whites:In a clean bowl add 4 large egg whites and 1/8 teaspoon white vinegar. Whip on medium-high until foamy, then gradually add half of the sugar (about 1/3 cup) and continue whipping. Whip approximately 3–4 minutes total until stiff peaks form. You want glossy peaks that hold shape without collapsing.Whisk Yolks and Sugar:In another bowl combine the remaining 1/3 cup sugar with 1 1/2 tablespoons warm water. Add the 4 egg yolks and 2 teaspoons vanilla. Whip on medium-high for 4 minutes until the mixture thickens and ribbons fall slowly from the whisk. This aeration gives body to the batter.Incorporate Oil and First Fold:Stream 2 tablespoons vegetable oil into the yolk mixture while mixing on medium, then fold in half of the whipped whites gently — fold with a spatula, cutting through the center and lifting to preserve air. Add half the dry ingredients and fold until just combined.Finish Batter and Bake:Fold in the remaining whipped whites and then the rest of the dry mix. Be gentle to avoid deflating. Divide batter evenly into prepared tins, tap lightly to release large bubbles, run a thin knife through batter, and bake for 20 minutes. The tops should spring back slowly when touched and a toothpick will come out clean.Cool Properly:Immediately tap tins on the bench from about 4 inches (10 cm) height and invert tins onto a wire rack to cool while still inside the tins — this reduces collapse and preserves height. After ~1 hour, run a thin knife around edges and turn cakes out. Trim edges for a neat finish if desired.Simple Syrup & Whip:Make simple syrup by dissolving 1/4 cup sugar in 1/4 cup boiling water and brush generously over cakes to keep them moist. Whip 2 cups cold heavy cream with 3 tablespoons powdered sugar, 3 tablespoons cocoa, and 1/2 teaspoon vanilla to stiff peaks, being careful not to overwhip.Assemble:Place one layer down, spread a thin layer of raspberry jam, arrange halved strawberries cut-side-down, then cover with chocolate whipped cream. Top with second layer, finish with more cream and berries. Chill briefly before slicing to set layers.

Storage Tips

Store assembled cake refrigerated in an airtight cake carrier for up to 3 days. If you need longer storage, freeze whole layers (without cream) for up to 3 months wrapped tightly in plastic and foil. To reassemble after thawing, let layers come to refrigerator temperature, brush with simple syrup if they feel dry, then add fresh whipped cream and jam. For best texture, avoid leaving the assembled cake at room temperature more than two hours if the filling contains fresh cream.

Ingredient Substitutions

If you don’t have cornstarch, substitute with an equal amount of additional all-purpose flour but expect a slightly firmer crumb. You can use melted unsalted butter in place of oil for a richer flavor, but the crumb will be a bit denser. For dairy-free options, use stabilized coconut cream whipped with powdered sugar and a cocoa of choice; note the flavor will shift and refrigeration is crucial to maintain structure.

Serving Suggestions

Serve slices with a dusting of cocoa or a few fresh berries for contrast. For afternoon tea, pair with a bright white tea or a citrusy oolong. For celebrations, add a mirror-glaze ganache drip or piped rosettes of whipped cream around the edge. Small edible flowers or mint sprigs make pretty garnishes without overpowering the classic flavors.

Cultural Background

This style of sponge is inspired by the traditional Victorian sponge — light whisked eggs provide lift rather than chemical leaveners or heavy fats. Sponges like this have long been a British teatime staple, often layered with jam and cream. The chocolate variation modernizes that tradition while honoring the technique of aeration and delicate folding.

Seasonal Adaptations

In summer swap raspberries for macerated peaches or mixed berries; in winter use spiced plum compote or orange marmalade for warmth. For holiday versions, fold a teaspoon of ground cinnamon into the cocoa and top with candied citrus peel. Adjust sugar slightly if the fruit compote is very sweet.

Meal Prep Tips

Plan ahead by baking layers one or two days in advance and storing them wrapped in the fridge. Whip the cream the day you assemble for the best texture. If you’re prepping multiple cakes, freeze baked layers individually and stack with parchment between them so you only thaw what you need.

There’s real joy in slicing this cake and watching the layers reveal themselves — it’s a simple pleasure that makes any moment feel a little more special. Try it once and then make it your own with seasonal fillings or a different frosting; the basic technique is so reliable that it rewards small creative flourishes.