Mary Berry’s chocolate biscuit cake is a no-bake fridge cake made with melted plain chocolate, butter and golden syrup. Crushed digestives and rich tea biscuits go in with chopped walnuts and sultanas. It takes under 15 minutes to assemble, then chills until firm.
Berry calls her version Chocolate Nut Tiffin Squares in the Ultimate Cake Book (2003). She notes they “tend to be a little crumbly and to fall apart, but are quite delicious.” For a special occasion, she suggests spreading extra melted chocolate on top.
The technique that matters most is melting the chocolate without overheating it. Berry writes in the same book to use “hot water, not boiling” under the bowl. Boiling water makes chocolate seize and turn stiff and grainy, so keep the heat gentle throughout.
Mary Berry Chocolate Biscuit Cake Recipe
Course: DessertCuisine: BritishDifficulty: Easy15
servings15
minutes310
kcalBerry’s Chocolate Nut Tiffin Squares from the Ultimate Cake Book (2003), filed under her no-bake chapter for children. Six ingredients stirred into melted chocolate and chilled in a roasting tin until set.
Ingredients
4 tablespoons golden syrup
175g (6 oz) butter or hard margarine
100g (4 oz) plain chocolate, broken into pieces
225g (8 oz) digestive biscuits, crushed
100g (4 oz) rich tea biscuits, crushed
100g (4 oz) walnuts, chopped
175g (6 oz) sultanas
Directions
- Grease the tin: Lightly grease a 30 × 23cm (12 × 9 in) roasting tin.
- Melt: Melt the syrup, butter and chocolate together in a heatproof bowl over a pan of hot water.
- Combine: Add the crushed biscuits, walnuts and sultanas and mix well.
- Fill the tin: Spoon into the prepared tin and level the surface.
- Chill and cut: Chill well until set, then cut into 15 squares, and serve from the fridge.
FAQs
Why does Berry use two types of biscuit?
Digestives have a wheaty, slightly sweet crumb that breaks down into a dense, almost fudgy base. Rich tea biscuits are drier and more brittle, so they shatter into finer, lighter fragments. Mixing the two gives variety in every bite instead of a uniform, heavy texture.
Berry doesn’t explain the split, but her two-to-one ratio is worth keeping. I tested it with all digestives and the result was heavier and greasy. The rich tea biscuits soak up more chocolate, which lightens the texture and helps the squares hold together.
How should you crush the biscuits?
Berry’s method across her books is consistent: put the biscuits in a freezer bag and pound them with a rolling pin. In Cooks the Perfect (2014), she specifies laying the bag flat on the work surface so it doesn’t burst. A resealable bag works best.
For cheesecake bases Berry aims for fine crumbs, but tiffin is different. You want a mix of powder and pea-sized chunks so the squares have something to bite into. A few firm whacks followed by one pass with the rolling pin does it.
How long does chocolate biscuit cake take to set?
Berry says “chill well until set” without a specific time, which can leave you guessing. In practice it needs at least two to three hours in the fridge for a firm set. Overnight is better because the chocolate hardens fully and the squares cut cleanly.
Don’t put it in the freezer to speed things up. Rapid chilling causes the chocolate to develop a white bloom on the surface, which is harmless but looks dull. A steady chill in the fridge gives you a glossy, even finish that cuts cleanly.
Can you make this without nuts?
The walnuts add crunch and a bitter edge that balances the sweetness of the syrup and sultanas. If you’re leaving them out, dried cherries or chopped dried apricots work well. Both bring a tart contrast that stops the squares tasting one-note sweet.
Berry’s Chocolate and Amaretti Bars from Cooks the Perfect (2014) take a different approach. She swaps digestives for amaretti, adds pine nuts and cocoa, then pours melted chocolate over the top. It’s the grown-up version if you’re serving after dinner.
What other no-bake treats are in this chapter?
Berry opens the chapter saying “a cake made without even turning on the oven has got to be a bonus.” The tiffin sits alongside Chocolate Cornflake Crunchies, Date Krispie Slices and No-cook Fudge. Her iced fairy cakes are there too, though those need the oven.
The whole section is designed for children to make with supervision. Berry writes that “children like to make small, colourful things” and sees these recipes as a first step into baking. Tiffin works well because there’s no oven and no sharp knives needed.
How do you store chocolate biscuit cake?
Berry’s instruction to “serve from the fridge” tells you where it lives. Keep it covered in the tin or transfer the squares to an airtight container. There’s no cream, eggs or flour to spoil, so it holds well for up to five days.
At room temperature the chocolate softens and the squares lose their clean edges within an hour. Take them out of the fridge just before cutting if you’re serving at a party. They’re meant to be eaten cold, which is part of the appeal.
