I’ll be honest: this cake nearly didn’t happen. I was halfway through whisking when I realised I’d used fridge-cold margarine and forgotten to soften the butter for the icing. Classic me, right? But guess what? That cold marg actually saved the sponge.
The first time I made this Butterscotch Traybake, from Mary Berry’s Fast Cakes, was on a grey Sunday when I craved something sweet but couldn’t bear the thought of a complicated recipe. This cake looks humble but vanishes within hours. It has a soft, light crumb, a golden crust, and a buttery, fudge-like icing that will take you straight back to school dinners—if only the dinner lady had trained at Le Cordon Bleu.
Let me show you how I got the sponge just right and made sure the icing disaster didn’t happen again. This one’s now my go-to for bake sales, birthdays, and those days when you just need something comforting, fast.
Why This Recipe Works
There’s real magic in this method: everything goes into one bowl, gets mixed, and baked. No creaming, no fuss. But here’s what makes it special:
- Cold margarine: Straight from the fridge, it gives the batter a tender crumb without greasiness. I didn’t expect this, but after trying softened butter (which made the cake dense), I’m convinced—cold marg is the way to go.
- Light muscovado sugar: This sugar adds a lovely toffee depth that caster sugar just can’t replicate. Dark brown sugar? Too heavy. The light muscovado is the perfect balance.
- The traybake format: It’s foolproof. No sinking centres, no worrying about raw middles. Just a consistently perfect bake.
Most butterscotch cakes can be too sweet or dry. This one strikes the right balance—golden, rich, and moist, with an icing that’s absolutely lush (if you get it right!).
Ingredients & Why They Matter
- Cold margarine (225g): Straight from the fridge. This creates a soft, light finish. (Don’t use spreadable butter—it makes the cake greasy.)
- Light muscovado sugar (225g): Adds depth and keeps the sponge moist. It’s the hero ingredient.
- Eggs (4 large): These help bind and lift the batter. Medium eggs make it dry—don’t skip the large ones.
- Self-raising flour (225g): A must for a light, airy sponge.
- Baking powder (1 tsp): Gives the cake that final boost.
For the icing:
- Butter (114g, softened): If it’s too cold, the icing won’t cream properly. I’ve learned to cube it and leave it out while the cake cools.
- Confectioners’ sugar (175g): Adds sweetness and helps structure the icing.
- Light muscovado sugar (25g): A game-changer that gives the icing a chewy, caramelly flavour.
- Vanilla (1 tsp): Rounds out the sweetness of the icing.
- Milk (2 tbsp): Helps loosen the icing and make it spreadable.
Making It Yours (Without Ruining It)
I’ve tried a few swaps—some work, some don’t:
- No margarine? Use chilled block butter (not spreadable). The same fridge-cold rule applies.
- Egg-free? I swapped the eggs for 4 tbsp of apple sauce. It works, but the cake is a bit denser.
- Gluten-free? I tried Doves Farm GF blend (1:1) with ½ tsp extra baking powder. The cake was a little crumbly but tasty.
- Nutty twist? Try adding 75g chopped pecans to the batter for extra crunch.
- Avoid dark muscovado sugar. It overpowers everything—trust me, I tried.
Mistakes I’ve Made (And How to Avoid Them)
| What Went Wrong | Why It Happens | How to Fix It |
|---|---|---|
| Icing turned gritty | Butter too cold or sugar not mixed well | Use softened butter and whisk for 2 minutes |
| Cake sank in the middle | Overmixed or oven too hot | Beat until just fluffy; check oven temp |
| Sponge felt greasy | Used spreadable butter | Stick to block margarine or butter |
| Edges dried out | Overbaked by 5 minutes | Check at 25–28 mins, not just at 30 |
How to Make Mary Berry’s Butterscotch Cake
- Preheat your oven to 180°C (160°C fan) / 350°F. Line a 30x23cm traybake tin with nonstick baking paper.
- In a large bowl, add cold margarine, muscovado sugar, eggs, self-raising flour, and baking powder.
- Beat with an electric mixer for 1–2 minutes until smooth and fluffy. The batter should be soft but thick, like soft-serve ice cream.
- Scoop the batter into the tin, level it with a spatula, and gently tap the tray to release any air bubbles.
- Bake for 28–30 minutes until golden brown and the edges start to pull away slightly from the sides.
- Let the cake cool completely in the tin (warm cake + icing = disaster—learn from my mistakes!).
- For the icing: Beat softened butter with icing sugar, muscovado sugar, vanilla, and milk until smooth and spreadable.
- Spread the icing evenly, using a warm spoon to smooth the top.
- Slice into 24 squares. Try not to eat four before serving. I failed, but you might succeed.
Tips from My Kitchen
- Weigh everything, even liquids. It’s more accurate, and Mary would approve.
- My fan oven runs hot, so I check the cake at 25 mins.
- I use a palette knife dipped in warm water to spread the icing smoothly.
- Want sharp cuts? Chill the cake before slicing. It firms up the icing and makes for clean, neat slices.
Storage & Serving
- Keeps: 4–5 days in an airtight tin (not the fridge—this makes the sponge firm up).
- Freezes: Wrap squares individually and freeze for up to 3 months.
- To serve: Lovely with whipped cream, a drizzle of caramel sauce, or just with a good cuppa. I recommend Yorkshire Gold tea.
FAQs – Real Baking Questions, Answered
Q: Can I use butter instead of margarine?
A: You can, but make sure it’s fridge-cold block butter. Softened or spreadable butter will make the cake greasy.
Q: Why is there muscovado sugar in the icing?
A: It adds a chewy, toffee-fudge flavour. Don’t skip it; it’s what makes the icing special.
Q: My cake is too sweet. Can I reduce the sugar?
A: I tested with 25g less sugar. The sponge was fine, but the icing needs the full amount to set properly.
Q: Can I bake this as a round cake?
A: I’ve tried it in two 8-inch round tins. Just reduce the bake time to 22–25 minutes.
Q: What’s the texture like?
A: Soft, light, and a bit fudgy. Not dense, but not airy either—just the right texture for a traybake.
