Mary Berry Chocolate Traybake

There’s a certain kind of chaos that only chocolate cake can fix. I made this one the first time while refereeing a living room pillow fight and trying to use up the last of a tin of cocoa powder. The goal? One bowl, minimal mess, maximum reward.

What surprised me? It came together ridiculously fast. The cocoa and hot water trick makes the sponge richer than most chocolate bakes I’ve tried, and because it uses margarine straight from the fridge, there’s no softening, creaming, or faffing about. The icing’s lush too—dark, glossy, and just soft enough to sink your teeth into.

This is the traybake you make when you’re short on patience but still want something that feels like comfort with a fork.

WHY THIS ONE WORKS SO WELL

Two things: blooming the cocoa and skipping the butter.

Mixing cocoa powder with hot water first gives you a deeper chocolate flavour—almost like you’ve used melted chocolate without the extra faff. And margarine (yep, cold from the fridge) keeps the sponge light, tender, and easy to pull off midweek.

It’s not overly sweet, either. The icing hits that proper cocoa punch without needing loads of sugar. It’s the kind of cake that tastes like it came from a bakery but feels like home.

INGREDIENTS + WHY THEY MATTER

Cocoa Powder (3 tbsp + ½ cup) – Deepens flavour when bloomed in hot water. Sift both for smoothness.
Hot Water (3 tbsp) – Unlocks the cocoa’s richness. Don’t skip or sub.
Margarine (225g, cold) – Straight from the fridge. Softens as you mix. Helps with that soft, even crumb.
Superfine Sugar (225g) – Dissolves quickly and keeps the sponge light.
Self-Rising Flour (275g) – Saves time. The lift is just right.
Baking Powder (1 tsp) – Extra insurance for a proper rise.
Eggs (4 large) – Room temp if possible for better blending.
Butter (85g, softened) – For the icing—adds structure and richness.
Icing Sugar (225g) – For that classic thick, glossy finish.
Milk (2 tbsp) – Softens the icing to spreadable.

MAKING IT YOURS (WITHOUT RUINING IT)

Want it richer? Add a splash of coffee to the cocoa water mix. It boosts the chocolate without tasting like coffee.
Need it dairy-free? Use dairy-free margarine and a plant-based milk. I’ve done it—it works.
Like it sweeter? Sift a bit of icing sugar over the top once it’s set. Simple and pretty.

MISTAKES I’VE MADE (AND HOW TO AVOID THEM)

What Went Wrong	Why It Happens	How to Fix It
Cake sank in the middle	Batter overmixed after adding eggs	Mix until just combined
Icing too soft	Butter too warm or overbeaten	Use room temp butter, beat slowly
Dry sponge	Overbaked by just a few minutes	Pull out as soon as it springs back

HOW TO MAKE MARY BERRY’S CHOCOLATE TRAYBAKE

1. Preheat and Prep
   Set oven to 180°C (160°C fan). Grease and line a 30x23cm traybake tin.
2. Bloom the Cocoa
   Mix cocoa powder and hot water in a bowl until smooth. Let cool slightly.
3. Make the Batter
   Add margarine, sugar, flour, baking powder, and eggs to the cocoa mixture. Beat until just smooth and fully blended.
4. Bake
   Pour into the prepared tin, level the top, and bake for 35–40 minutes. It should spring back when lightly pressed.
5. Cool
   Let the cake cool completely in the tin before icing.
6. Make the Icing
   Beat softened butter with cocoa powder, icing sugar, and milk until thick and spreadable. It should hold its shape but still be soft.
7. Ice and Serve
   Spread icing over the cooled cake. Let it set, then cut into squares and serve.

TIPS FROM MY KITCHEN

I use a small offset spatula to swirl the icing—makes it look more polished than it is.
If the cocoa mixture is still hot, it’ll melt the margarine—wait a minute before adding everything else.
Store it in the tin, covered with foil. Keeps it from drying out without needing the fridge.

STORAGE + SERVING

Keeps: Up to 5 days in a sealed container at room temp
Freezes: Yes, with or without icing. Slice and freeze between layers of baking paper
Serve with: A scoop of vanilla ice cream, a coffee, or just straight from the tin

FREQUENTLY ASKED QUESTIONS

Q: Can I use butter instead of margarine?
Yes, but soften it first. It gives a slightly firmer crumb.

Q: Can I skip the icing?
You can—but it’s not the same. Try a dusting of icing sugar if you’re going plain.

Q: Why does my cake crack on top?
Usually the oven’s too hot. Stick to 160°C fan and use the middle shelf.

Try More Recipes:

• Mary Berry American Chocolate Wedding Cake Recipe
• Mary Berry Chocolate Mirror Cake
• Mary Berry White Chocolate and Vanilla Cake