Mary Berry Walnut and Chocolate Brownies

There’s something a bit nostalgic about these brownies for me—they’re the kind of traybake I remember making in the 90s when everyone had a Mary Berry cookbook on the kitchen shelf. They’re lighter than your average fudge brownie, more cake-like in texture, and packed with toasted walnuts that make them feel like a proper treat for grown-ups.

The first time I tried this recipe, I was a bit skeptical—it uses margarine instead of butter, and the batter felt far too fluffy for what I thought a brownie should be. But once they cooled and I cut into those glossy, crisp tops with chewy middles and crunchy nuts? I got it. Completely.

If you’re looking for a dependable brownie that travels well and pleases even the fussiest snackers, let me show you what makes this one a quiet legend.

What Makes This Recipe Special

Unlike the super-gooey brownies you get nowadays, this one leans more towards a cross between a cake and a brownie—with a slightly crisp top and tender, almost mousse-like middle. The sugar-to-flour ratio is higher than most cakes, which keeps it soft and sweet even after a couple of days.

Also? The walnuts aren’t just a garnish—they’re mixed in generously, adding a bitter edge that balances all that sweetness. I didn’t expect them to be such a hero in the bake, but they really are.

INGREDIENTS + WHY THEY MATTER

• Plain chocolate (75g) – I used 54% dark, which gave a rich but not overly bitter flavour. Anything darker and it’ll overpower the walnuts.
• Margarine (100g) – This helps keep the texture soft and the batter fluffy. I tested it with butter too, and the result was richer, but firmer.
• Caster sugar (350g) – Yes, it’s a lot! But it gives that classic crackly top and caramelised edge. I once tried cutting it by 50g and instantly regretted it—don’t skimp here.
• Eggs (3) – Whisked until fluffy, they help hold the structure and keep things airy.
• Plain flour (120g) – Just enough to give them structure. Too much, and they go cakey.
• Baking powder (1 tsp) – Lifts the batter just enough to keep it from being dense.
• Walnuts (175g) – Toast them first for even more depth. I chopped mine quite roughly—bigger bits = better crunch.

Making It Yours (Without Ruining It)

Swap the nuts: Pecans work brilliantly here if you’re out of walnuts. Hazelnuts are tasty but make it more of a Ferrero vibe.

Gluten-free option: I tried it with a plain GF flour blend and ¼ tsp xanthan gum—still soft, still lovely.

Add-ins I’ve tried:

• 75g dried cranberries (tart + sweet = brilliant contrast)
• ½ tsp ground cinnamon for a cosy twist
• A splash of vanilla—it doesn’t need it, but it softens the chocolatey edge

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

What Went Wrong	Why It Happens	How to Fix It
Top burned, middle raw	Oven too hot	Check oven temp with thermometer; bake middle shelf
Flat and dense brownies	Overmixed after adding flour	Fold gently—just until combined
Too sweet, not enough contrast	Used milk chocolate	Use dark chocolate—at least 50% cocoa
Walnuts went soggy	Didn’t toast or used old nuts	Use fresh walnuts and toast for 5 mins

HOW TO MAKE MARY BERRY’S WALNUT AND CHOCOLATE BROWNIES

1. Prep your tin: Heat oven to 180°C (350°F). Grease and line a 30×23cm traybake tin.
2. Melt chocolate + margarine: Gently melt in a heatproof bowl over a pan of simmering water. Stir until smooth, then let it cool slightly.
3. Whisk eggs + sugar: In a large bowl, whisk until thick and pale. This gives the brownies their lift and crackly top.
4. Mix it all together: Pour in the cooled chocolate mixture and stir gently. Sift in the flour and baking powder, fold in. Stir through the walnuts.
5. Bake: Pour into the tin, smooth the top, and bake for about 40 minutes. The top should be set, but the middle will still feel soft.
6. Cool + slice: Cool in the tin for 10 minutes before turning out. Slice with a hot knife for perfect squares.

TIPS FROM MY KITCHEN

• I line the tin with overhanging baking paper so I can lift the whole slab out—much easier to slice.
• If you’re serving these warm (and you should at least once), a little crème fraîche or sour cherry compote cuts the sweetness beautifully.
• I always toast my walnuts in the oven for 5 mins at 160°C—they’re just better that way. More flavour, less soggy texture.

STORAGE + SERVING

• Room temp: Airtight tin, up to 3 days. They stay soft!
• Fridge: Up to 5 days, but bring to room temp before eating.
• Freezer: Freeze squares wrapped in baking paper for up to 3 months. Defrost at room temp.

FREQUENTLY ASKED QUESTIONS

Q: Can I make this without nuts?
A: Absolutely. Just leave them out or swap for chocolate chunks if you want something extra.

Q: Are they more cakey or fudgy?
A: Cakey—but still moist and rich. They’re not dense like American-style brownies.

Q: Can I use butter instead of margarine?
A: Yes! The result is a touch firmer but still delicious. Use the same amount.

Q: Can I use a smaller tin?
A: You can, but your brownies will be thicker—bake 5–10 mins longer and check with a skewer.

Try More Recipes:

• Mary Berry ​Chocolate Chip Brownies
• Mary Berry Ultimate Chocolate Brownies
• Mary Berry Salted Caramel Brownies