My Darker Version of the London Viral Chocolate Cake
My Darker Version of the London Viral Chocolate Cake is a medium Western recipe that serves 12. 350 calories per serving. Recipe by Anna | Pastry Arts on YouTube.
Prep: 2 hrs 55 min | Cook: 25 min | Total: 3 hrs 40 min
Cost: $17.00 total, $1.42 per serving
Ingredients
- 200 ml Heavy Cream (high‑fat, for ganache)
- 150 g Dark Chocolate (54% cocoa, chopped)
- 2 tbsp Cocoa Powder (regular cocoa, for ganache)
- 1 tbsp Glucose Syrup (or neutral honey, for shine)
- 200 ml Strong Coffee (hot, unsweetened)
- 50 g Dutch‑Process Cocoa Powder (darker, smoother flavor)
- 50 g Regular Cocoa Powder (adds depth and acidity)
- 100 g Unsalted Butter (cut into cubes)
- 100 ml Milk (whole milk preferred)
- 1 tsp Apple Cider Vinegar (provides acidity for baking soda)
- 2 large Eggs (weighed for accuracy, about 100 g total)
- 150 g Bread Flour (strong flour for structure)
- 150 g Granulated Sugar (helps retain moisture)
- 1 tsp Baking Soda
- 1 tsp Baking Powder
- 200 g Fresh Cranberries (rinsed)
- 100 ml Port Wine (red port, for cooking the filling)
- 2 g Agar‑Agar Powder (about 1 tsp, for setting the filling)
Instructions
Make Dark Chocolate Ganache
Heat the heavy cream in a saucepan until just simmering (about 80°C). Whisk in the cocoa powder and glucose syrup, then add the chopped dark chocolate. Stir until smooth.
Time: PT15M
Temperature: 80°C
Blend Ganache into a Glossy Emulsion
Transfer the warm ganache to a blender and blend on low for 30 seconds until glossy and bubble‑free. Let it cool to room temperature, then refrigerate until firm.
Time: PT5M
Set Ganache
Cover the ganache and chill in the refrigerator until firm enough to pipe (about 30 minutes).
Time: PT30M
Prepare Coffee‑Cocoa Mixture
Pour the hot coffee over the regular cocoa powder in a bowl, stir until fully dissolved and the mixture darkens.
Time: PT5M
Melt Chocolate and Butter
In a separate saucepan, melt the dark chocolate with the butter over low heat, stirring until smooth.
Time: PT5M
Temperature: 60°C
Combine Wet Ingredients
Add the coffee‑cocoa mixture, melted chocolate‑butter, milk, and apple cider vinegar to a mixing bowl. Whisk in the eggs one at a time.
Time: PT5M
Add Dry Ingredients
Sift together the Dutch‑process cocoa, regular cocoa, bread flour, sugar, baking soda, and baking powder. Fold into the wet mixture until just combined.
Time: PT5M
Bake the Sponge
Line the 20 × 30 cm baking pan with parchment. Pour the batter into an even layer and bake at 180°C for 15‑19 minutes, or until a skewer comes out clean and the cake springs back.
Time: PT18M
Temperature: 180°C
Cool the Sponge Completely
Remove the cake from the oven, let it sit in the pan for 5 minutes, then lift onto a cooling rack. Cool at room temperature until completely cold (about 30 minutes).
Time: PT30M
Make Cranberry‑Port Filling
Combine cranberries and port wine in a saucepan. Bring to a boil, then add agar‑agar powder. Boil for 2 minutes, stirring constantly. Remove from heat and blend until smooth.
Time: PT15M
Temperature: 100°C
Set the Filling
Pour the hot filling into a shallow dish, let it cool to room temperature, then refrigerate until firm (about 30 minutes). Once set, blend again for a silky texture.
Time: PT30M
Trim and Layer the Sponge
Using a ruler, cut the cooled sponge into three equal rectangles (approximately 10 × 20 cm each).
Time: PT5M
Assemble the Cake
Place the first sponge layer on a serving plate. Pipe a thin coat of ganache over it. Spread a thin layer of the cranberry‑port filling on top. Repeat with the second layer (ganache only) and third layer (ganache only). Smooth the sides and top with a spatula.
Time: PT20M
Final Chill
Refrigerate the assembled cake for at least 30 minutes so the ganache sets and the layers fuse.
Time: PT30M
Finish and Serve
Dust the top with a light sprinkling of Dutch‑process cocoa for a velvet finish. Slice with a warm knife and serve.
Time: PT5M
Nutrition Facts
- Calories
- 350
- Protein
- 5 g
- Carbohydrates
- 45 g
- Fat
- 18 g
- Fiber
- 3 g
Dietary info: Vegetarian, Contains gluten, Contains dairy
Allergens: Dairy, Eggs, Gluten, Soy (cocoa), Seafood (agar‑agar derived from seaweed)
Ingredient Substitutions
- Instead of Heavy Cream: full‑fat coconut milk
- Instead of Dark Chocolate: 70% cocoa chocolate
- Instead of Cocoa Powder: Dutch‑process cocoa (will change color)
- Instead of Glucose Syrup: honey, corn syrup
- Instead of Strong Coffee: espresso, strong brewed tea
- Instead of Dutch‑Process Cocoa Powder: regular cocoa (will be lighter)
- Instead of Regular Cocoa Powder: Dutch‑process cocoa
- Instead of Unsalted Butter: margarine
- Instead of Milk: 2% milk, almond milk
- Instead of Apple Cider Vinegar: white vinegar, lemon juice
- Instead of Eggs: egg replacer
- Instead of Bread Flour: all‑purpose flour (slightly less structure)
- Instead of Granulated Sugar: coconut sugar
- Instead of Baking Soda: baking powder (adjust amount)
- Instead of Baking Powder: baking soda + extra acid
- Instead of Fresh Cranberries: frozen cranberries
- Instead of Port Wine: red wine, ruby wine
- Instead of Agar‑Agar Powder: gelatin (non‑vegetarian)
Equipment Needed
- Saucepan
- Blender
- Mixing Bowls
- Baking Pan
- Parchment Paper
- Kitchen Scale
- Spatula
- Piping Bag (optional)
- Warm Knife (optional)
- Cooling Rack
Critical Steps — Do Not Skip
- Ensuring the ganache is blended without lumps using a blender.
- Boiling the agar‑agar mixture for a full 2 minutes to guarantee setting.
- Allowing the sponge to cool completely before cutting.
- Using a warm knife for clean slices.
Chef Tips from the Video
- Add a pinch of salt to the ganache for depth of flavor.
- Replace part of the coffee with espresso for an even richer chocolate taste.
- If you prefer a brighter red layer, add a few drops of natural beet juice after the agar sets.
Troubleshooting
Ganache is grainy or has lumps.
Re‑blend the ganache while still warm, or gently re‑heat and whisk until smooth. Ensure cocoa powder is fully dissolved before adding chocolate.
Cranberry filling loses its red color.
Do not over‑boil; keep the boil to exactly 2 minutes and cool quickly. Use a red port wine for deeper hue.
Sponge cracks when cutting.
Make sure the sponge is completely cooled and use a warm, sharp knife. Slice with a gentle sawing motion.
Storage
Refrigerator: Store the whole cake, covered, for up to 4 days.
Freezer: Wrap tightly in plastic and foil; freeze for up to 2 months. Thaw in refrigerator before serving.
Room temperature: Do not keep at room temperature longer than 2 hours due to ganache.
Make-Ahead Tips
- Prepare the ganache a day ahead and keep refrigerated.
- Bake the sponge layers up to 2 days in advance; store wrapped in the fridge.
- The cranberry‑port filling can be made 24 hours ahead; it will firm up further.
Frequently Asked Questions
What is the cultural significance and history of a black chocolate cake in Western dessert tradition?
Black chocolate cake, popularized by movies like Matilda, represents a dramatic, adult‑oriented twist on classic chocolate cake. Its deep color is achieved with high‑cocoa ingredients rather than food coloring, reflecting a modern desire for natural, intense flavors.
What are the traditional regional variations of chocolate cake in European cuisine?
European chocolate cakes range from the light, flour‑based German chocolate cake to the dense, flourless French gâteau au chocolat. This recipe leans toward the German style with a tender sponge but adds a unique ruby cranberry‑port layer for a grown‑up touch.
How is a black chocolate cake traditionally served in Western celebrations?
It is often served as a centerpiece dessert for birthdays, anniversaries, or holiday gatherings, sliced with a warm knife to reveal its glossy ganache and hidden ruby layer, and paired with coffee or dessert wine.
What occasions or celebrations is a black chocolate cake traditionally associated with in Western culture?
Because of its dramatic appearance, it is popular for milestone birthdays, graduation parties, and evening dinner parties where a sophisticated, adult‑friendly dessert is desired.
What authentic traditional ingredients are used in a classic chocolate cake versus this black chocolate cake?
Traditional chocolate cakes often rely on cocoa powder, sugar, butter, eggs, and milk. This recipe adds coffee for depth, Dutch‑process cocoa for a smoother dark color, and a cranberry‑port filling with agar‑agar for a natural ruby hue, staying true to natural coloring.
What other Western desserts pair well with this black chocolate cake?
Serve it alongside a dollop of vanilla whipped cream, a scoop of salted caramel ice cream, or a glass of ruby port or espresso for complementary flavors.
What are the most common mistakes to avoid when making this black chocolate cake?
Common errors include adding cocoa directly to cold cream (causes lumps), not boiling agar‑agar long enough (won’t set), cutting the sponge while warm (causes crumbling), and over‑mixing the batter (creates a dense cake).
Why does this recipe use vinegar with baking soda instead of using Dutch‑process cocoa alone?
Dutch‑process cocoa is neutral, so the baking soda needs an acid to create carbon dioxide bubbles. The vinegar provides that acidity, ensuring the cake stays light despite the dense chocolate batter.
Can I make the black chocolate cake ahead of time and how should I store it?
Yes. Bake and cool the sponge layers, then wrap them tightly and refrigerate for up to 2 days. The ganache can be prepared a day ahead, and the assembled cake keeps well covered in the fridge for up to 4 days.
What texture and appearance should I look for when the ganache is ready?
The ganache should be glossy, smooth, and thick enough to hold its shape when piped, without any visible air bubbles. It should have a deep, almost black sheen.
What does the YouTube channel Anna | Pastry Arts specialize in?
The YouTube channel Anna | Pastry Arts specializes in elegant pastry and cake tutorials, focusing on modern techniques, natural flavor development, and visually striking desserts without relying on artificial coloring.
How does the YouTube channel Anna | Pastry Arts' approach to chocolate cake differ from other pastry channels?
Anna | Pastry Arts emphasizes natural darkening agents like coffee and Dutch‑process cocoa, uses scientific methods such as agar‑agar for fruit fillings, and prioritizes stability and texture over decorative frosting, setting her apart from channels that rely heavily on buttercream and food coloring.
Last updated: November 9, 2026
