Mary Berry’s Chocolate Mirror Cake Recipe

The first time I attempted this cake, I had absolutely no business going near a mirror glaze. After binge-watching a few too many baking shows, I thought to myself, “How hard can it be?” Famous last words.

What followed was a baking disaster. The glaze split, the sponge sank in the middle, and my kitchen resembled a chocolate scene from a horror film. Yet, I couldn’t shake the idea of that beautiful glossy finish. So, I tried again. And again. By the third attempt, I finally cracked it—the perfect temperature, the ideal texture, and most importantly, the right patience. Let me walk you through the steps I took to get it just right.

What Makes This Cake Special

• Light, airy sponge – The sponge is delicate enough to soak up the glaze without sinking.

• Real mirror glaze – Achieving that glossy finish requires the right combination of gelatin, chocolate, and patience.

• Rich and beautiful contrast – The glaze doesn’t just add shine, it brings a rich, ganache-like texture to complement the light sponge.

• The shine lasts – The glaze stays glossy, even in the fridge. I was pleasantly surprised when I found it didn’t lose its lustrous sheen overnight.

Ingredients + Why They Matter

For the Cake:

• 4 extra-large eggs – The base for a light, airy texture. Whip them to the ribbon stage for optimal lift.

• 125g sugar – Granulated sugar works fine, but caster sugar gives a smoother texture and finer crumb.

• 125g all-purpose flour – Sift it! It keeps the sponge light and fluffy.

• 1½ tsp baking powder – A gentle rise for the sponge, but don’t overdo it—too much can cause the cake to dome.

• ¼ tsp salt – Balances out the sweetness of the cake.

• 55g melted butter – Adds richness without making the sponge too heavy. Fold it in last to preserve the air bubbles.

For the Mirror Glaze:

• 14g powdered gelatin (2 envelopes) – The magic ingredient that gives the glaze its shine. Just don’t let it boil—too much heat will ruin it.

• 225g sugar – Provides sweetness and structure to the glaze.

• 75g cocoa powder – For deep, rich chocolate flavor. Use a high-quality cocoa—it really makes a difference.

• 75ml heavy cream – The key to a glossy, smooth texture.

• 240ml warm water – Split into two portions for blooming the gelatin and thinning the glaze.

• 55g dark chocolate – Adds depth and smoothness to the glaze. Dark is best for a more intense flavor.

Making It Yours (Without Ruining It)

• Flavor variations: Want to add more depth to the sponge? A teaspoon of vanilla or espresso powder works wonders.

• Substitute chocolate: Don’t have dark chocolate? Semi-sweet works too, though it won’t have quite the same depth.

• Gluten-Free: I’ve tested this recipe with a 1:1 gluten-free flour blend. The sponge is a bit more fragile but still delicious.

• Shortcut: If you’re pressed for time, you can use a sturdy boxed sponge cake, but be cautious with anything too soft or crumbly.

Mistakes I’ve Made (and How to Avoid Them)

1. Overheating the glaze: Too much heat causes the gelatin to break down and ruin the finish. Keep a close eye on the temperature, especially when adding the chocolate.

2. Not cooling the sponge completely: If the sponge is even slightly warm, the glaze will melt right off. Make sure your cake is at room temperature before applying the glaze.

3. Not using the right glaze consistency: The glaze needs to be thick enough to coat, but still runny enough to spread. Let it cool to the perfect pouring temperature (around 30-35°C/86-95°F).

4. Rushing the process: Patience is key here. Don’t try to rush through the glaze or the result will be lackluster. The magic happens in the details.

Instructions:

1. Preheat the Oven:

• Preheat your oven to 180°C (350°F). Grease and line a 9-inch springform tin with parchment paper.

2. Prepare the Sponge:

• In a mixing bowl, whisk the eggs and sugar together until the mixture becomes thick and pale (ribbon stage).

• Sift the flour, baking powder, and salt into the bowl and gently fold them in to preserve the air.

• Drizzle the melted butter around the edge of the bowl, then fold it in carefully.

3. Bake:

• Pour the batter into the prepared tin and level it out. Bake for about 30 minutes, or until the cake is pale golden and the edges pull away from the tin.

• Let the cake cool in the tin for a few minutes, then transfer it to a wire rack to cool completely.

4. Prepare the Gelatin:

• In a small bowl, bloom the gelatin by adding it to 120ml of warm water. Stir and leave it to thicken. Make sure not to boil the gelatin.

5. Make the Glaze:

• In a saucepan, combine the sugar, cocoa powder, cream, and 120ml of warm water. Bring it to a boil, then stir in the dark chocolate until fully melted and smooth.

6. Finish the Glaze:

• Stir in the bloomed gelatin and strain the mixture through a fine sieve into a bowl to remove any lumps.

• Let the glaze cool for 15 minutes until it becomes thick but still pourable.

7. Glaze the Cake:

• Place the cooled cake on a wire rack set over a tray. Slowly pour the glaze over the center of the cake, allowing it to drip down the sides.

• Use a palette knife to smooth the glaze and cover any uncovered spots. Let the glaze set for 30 minutes before transferring the cake to a serving plate.

Tips:

• Chill the Sponge: Before glazing, chill the sponge in the fridge for a while. This helps the glaze cling to the surface.

• Glaze Temperature: Always use a digital thermometer to ensure the glaze is around 30–35°C when poured for the best shine.

• Strain the Glaze: Strain the glaze twice—once while preparing and again before pouring it over the cake to get a smooth finish.

Storage & Serving:

• Fridge: The cake can be stored in a covered container in the fridge for up to 3 days, and the glossy finish will remain intact.

• Freezer: You can freeze the sponge without the glaze. Once thawed, add the glaze to get the best results.

• Serving Suggestions: Serve with a dollop of whipped cream or a drizzle of raspberry purée for a nice contrast to the rich chocolate.

Frequently Asked Questions:

Q: Can I make this cake ahead of time?
A: Yes! You can bake the sponge the day before and glaze it the next day. Just remember to chill the sponge before glazing.

Q: My glaze isn’t shiny. What did I do wrong?
A: The glaze may have been too cool when poured or over-stirred. Ensure the glaze is about 32°C and avoid mixing it too much.

Q: Can I double the glaze for a thicker coat?
A: No need to double the glaze. It’s meant to be a thin layer, and doubling it could cause it to slump or crack.

Q: Can I use agar instead of gelatin?
A: Agar can be used, but it won’t give the same glassy finish as gelatin. Gelatin is what provides the signature shine.

Try These More Recipes:

• Mary Berry’s American Chocolate Cake

• Mary Berry’s Tiny Chocolate Cupcakes

• Mary Berry’s Chocolate Yoghurt Cake

Ingredients:

For the Sponge:

• 4 extra-large eggs

• 125g sugar

• 125g all-purpose flour (sifted)

• 1½ tsp baking powder

• ¼ tsp salt

• 55g salted butter (melted and cooled)

For the Mirror Glaze:

• 2 envelopes (7g each) powdered gelatin

• 225g sugar

• 75g cocoa powder

• 75ml heavy cream

• 240ml warm water (split)

• 55g dark chocolate

Directions:

1. Preheat the Oven:
   Preheat your oven to 180°C (350°F). Grease and line a 9-inch springform tin with parchment paper.

2. Prepare the Sponge:

   • Whisk the eggs and sugar together until thick and pale.

   • Gently fold in the sifted flour, baking powder, and salt.

   • Fold in the melted butter until just combined.

3. Bake:

   • Pour the batter into the prepared tin and smooth the top.

   • Bake for 30 minutes or until the cake is golden and the edges begin to pull away from the sides of the tin.

   • Allow the cake to cool completely.

4. Prepare the Gelatin:

   • Bloom the gelatin in 120ml of warm water. Stir to dissolve and leave it to thicken.

5. Make the Glaze:

   • In a saucepan, combine the sugar, cocoa powder, heavy cream, and 120ml of warm water.

   • Heat gently, stirring until the sugar dissolves and the mixture is smooth.

   • Remove from heat and stir in the dark chocolate until fully melted.

   • Stir in the bloomed gelatin.

   • Strain the glaze through a fine sieve to remove any lumps or bubbles.

   • Let it cool for 15 minutes until it’s thick but still pourable.

6. Glaze the Cake:

   • Place the cooled cake on a wire rack set over a tray to catch any excess glaze.

   • Slowly pour the glaze over the center of the cake, letting it drip down the sides.

   • Let the glaze set for 30 minutes before transferring the cake to a serving plate.

Notes:

• Glaze Temperature: For best results, the glaze should be between 30–35°C. If it’s too cold, it won’t flow smoothly.

• Strain the Glaze: Always strain the glaze to remove bubbles and clumps, ensuring a flawless finish.

• Chill the Sponge: To help the mirror finish lock in place, chill the sponge in the fridge before glazing.