I made this cake for my mum’s birthday, thinking I was being clever by prepping it the night before. Turns out, mousse doesn’t rush. The next morning, the top looked like a shiny chocolate swamp. Crisis? Almost. I saved it with a quick blast in the freezer (more on that below), and when I remade it properly, I finally saw why this cake deserves its name: it’s pure celebration, without the faff.
You get Mary Berry’s signature easy sponge base—but it’s the mousse that steals the show. It’s rich but light, impressive but unfussy. If you’re after a cake that looks elegant without sugar thermometers or stacking layers, this is it.
Why This Recipe Works
Most mousse cakes get it wrong—they’re either too soft to slice or too stiff to enjoy. Mary Berry’s version hits the perfect balance, thanks to:
- A single sponge layer that’s soft but sturdy enough to hold the mousse.
- Real whipped cream in the mousse (no eggs, no gelatin), so it stays cloud-like and smooth.
And don’t skip the brandy brushed on the warm sponge—it adds depth without making the cake taste boozy. Even my mum, who usually avoids alcohol in desserts, approved.
Key Ingredients & Why They Matter
- 25g unsweetened cocoa powder – Forms the sponge’s deep chocolate base. Avoid drinking chocolate—it’s too sweet and weak.
- Boiling water – “Blooms” the cocoa for richer flavor.
- Caster sugar – Gives light sweetness without heaviness.
- Self-raising flour + 1 tsp baking powder – Essential for the perfect rise. Don’t substitute plain flour unless you add enough raising agent.
- Baking spread (like Stork) – Creams easily and bakes evenly. Butter works too but can make the sponge denser.
- 300g dark chocolate (40–50%) – This is key. Too bitter (70%+) = chalky mousse. Too sweet = sickly. 45% is your sweet spot.
- 450ml whipping cream – Cold and whipped only to soft peaks. Overwhipping turns the mousse grainy.
Want to Mix It Up? Try This
- No brandy? Skip it or swap for cooled coffee or orange juice. Coffee gave it a lovely tiramisu vibe.
- Gluten-free? Works well with GF self-raising flour—just watch the bake time.
- Dairy-free? Still testing—oat cream sets okay but lacks that rich mouthfeel.
- Add fruit? Stick to raspberries or blueberries. Strawberries look pretty but leak too much juice.
Mistakes I’ve Made (So You Don’t Have To)
| What Went Wrong | Why It Happened | How to Fix It |
|---|---|---|
| Mousse didn’t set | Chocolate was too warm or cream was overwhipped | Let chocolate cool; whip cream to soft peaks |
| Dense sponge | Forgot the baking powder | Double-check your flour type |
| Mousse soaked sponge | Didn’t cool cake fully before adding mousse | Let cake cool completely first |
| Bitter mousse | Used 70%+ dark chocolate | Stick to 40–50% cocoa solids |
How to Make Mary Berry’s Celebration Mousse Cake
1. Prep the tin
Line a deep 20cm springform tin with parchment, including the sides—this mousse rises higher than you’d think.
2. Make the sponge
Mix cocoa and boiling water into a smooth paste. Add caster sugar, self-raising flour, baking powder, baking spread, and eggs. Beat until smooth. Bake at 160°C fan (180°C conventional) for 20–25 minutes.
3. Soak the sponge
While still warm, brush over brandy (or your chosen liquid). Then let the cake cool completely in the tin.
4. Make the mousse
Melt the chocolate gently and let it cool slightly. Whip cold cream to soft peaks. Gently fold the chocolate into the cream with a spatula until fully combined and glossy.
5. Assemble
Spoon the mousse over the cooled sponge. Level the top, cover the tin, and chill in the fridge overnight.
6. Finish and serve
Dust with cocoa, top with berries, and slice with a warm knife. Serve with pouring cream for full effect.
Kitchen Tips That Make a Difference
- Wrap the tin base in foil while chilling—keeps fridge smells out and helps insulate.
- Use a silicone spatula for folding mousse—it keeps the texture light and airy.
- Mousse still soft after 4 hours? Pop the whole cake in the freezer for 20 minutes before serving.
- Slice with a knife dipped in hot water for clean edges.
Storage & Serving Suggestions
- Fridge: Keeps well for 3–4 days in an airtight container.
- Freezer: OK for short emergency chill, but not ideal for long-term storage—mousse texture suffers.
- Serve with: Fresh berries, a drizzle of raspberry coulis, or just a generous pour of double cream. Avoid ice cream—it overpowers the mousse.
Frequently Asked Questions
Q: Can I make it ahead?
Yes—it’s actually better made the day before. Just add berries right before serving to avoid juice bleeding.
Q: Can I make just the sponge?
Technically, yes. But the mousse is the whole point—otherwise it’s just a nice chocolate sponge.
Q: Best chocolate to use?
Look for good-quality dark chocolate around 45%. I love Lindt 50% or Green & Black’s Cooking Chocolate. Avoid compound chocolate—it can turn grainy.
Q: Do I really need a springform tin?
Yes. You won’t get the cake out cleanly without it. The mousse clings to regular tins.
Try More of Mary’s Classics:
- Chocolate Roulade
- Chocolate Victoria Sandwich
- Cut-And-Come-Again Cake
- Coffee Victoria Sandwich
