Mary Berry Blueberry Traybake Recipe

There’s a reason Mary Berry has been the nation’s favourite baker for decades; the woman simply doesn’t miss. Her blueberry traybake is proof of that. One tin, minimal fuss, and you end up with something that looks like it came from a proper bakery. I’ve made this more times than I can count, and it earns a compliment every single time.

What Is Mary Berry’s Blueberry Traybake?

Mary Berry’s blueberry traybake is a light, moist vanilla sponge studded with juicy blueberries, baked in a rectangular tin and finished with a simple lemon glaze or dusting of icing sugar. It cuts into neat squares, travels well, and works just as beautifully at a summer garden party as it does on a rainy Tuesday with a cup of tea. That versatility is exactly why traybakes have always been a staple of British home baking.

Ingredients You’ll Need

For the Traybake Sponge

• 225g (8oz) softened unsalted butter
• 225g (8oz) caster sugar
• 275g (10oz) self-raising flour
• 2 tsp baking powder
• 4 large eggs
• 4 tbsp milk
• 1 tsp pure vanilla extract
• 300g (10oz) fresh blueberries, divided (see below)

For the Lemon Glaze (Optional but Recommended)

• 150g (5oz) icing sugar, sifted
• 2–3 tbsp fresh lemon juice
• Zest of 1 lemon

FYI, fresh blueberries work best here. Frozen blueberries release too much water during baking and can make the sponge soggy in patches. If fresh ones aren’t available, toss frozen ones in a tablespoon of flour before folding in; it helps absorb some of that extra moisture.

How to Make Mary Berry’s Blueberry Traybake

Step 1: Prep Your Tin and Oven

Preheat your oven to 180°C / 160°C fan / Gas 4. Grease and line a 30x23cm (12×9 inch) traybake tin with baking parchment, letting it overhang the sides slightly. That overhang saves you from the indignity of trying to lever a whole traybake out of a tin with a butter knife.

Step 2: Make the All-In-One Batter

This is Mary Berry’s genius all-in-one method; everything goes into one bowl at the same time. Add the softened butter, caster sugar, flour, baking powder, eggs, milk, and vanilla extract to a large mixing bowl. Beat with an electric hand mixer for about 2 minutes until the batter is smooth, pale, and well combined.

The batter should have a soft dropping consistency; it falls off the spoon easily but holds its shape briefly. If it feels too stiff, add a splash more milk.

Step 3: Fold In the Blueberries

Take two-thirds of your blueberries and fold them gently into the batter by hand using a spatula. Don’t use the mixer for this step; you’ll crush the berries and turn your beautiful pale batter a rather unfortunate shade of grey-purple. Reserve the remaining blueberries for the top.

Step 4: Fill the Tin and Top with Blueberries

Pour the batter into your prepared tin and spread it evenly into all four corners. Scatter the reserved blueberries over the surface, pressing them down very lightly so they partially sink in during baking. This gives you blueberries throughout the sponge and a beautiful studded top. IMO, that detail makes a real difference to the finished look.

Step 5: Bake

Bake for 35–40 minutes until the sponge is golden, well-risen, and a skewer inserted into the centre comes out clean. The top should feel springy when you press it gently in the centre. If it springs back, it’s done.

Resist opening the oven before the 30-minute mark. That sudden drop in temperature is the leading cause of sunken traybakes, and no amount of icing sugar camouflages a truly sunken centre. Ask anyone who’s tried.

Step 6: Cool and Glaze

Leave the traybake to cool completely in the tin, and I mean completely, not just mostly. Once cool, mix the sifted icing sugar with fresh lemon juice until you get a smooth, pourable glaze. Drizzle it over the traybake and scatter over the lemon zest. The lemon cuts through the sweetness of the blueberries beautifully and lifts the whole thing.

Once the glaze sets (about 20 minutes), lift the traybake out using the parchment overhang and slice into squares.

Tips for the Best Mary Berry Blueberry Traybake

• Room temperature ingredients matter. Cold butter straight from the fridge won’t cream properly, even in an all-in-one batter. Take it out at least an hour before you start.
• Don’t overfill the tin. A 30x23cm tin is the right size for this quantity. Go smaller, and the sponge won’t cook through evenly in the centre.
• Toss blueberries in flour. Coat them lightly in a teaspoon of flour before folding in; it stops them all sinking to the bottom during baking.
• Storage: Keep in an airtight tin at room temperature for up to 3 days, or refrigerate for up to 5 days. The lemon glaze stays glossy, and the sponge actually gets a little more moist overnight.

Frequently Asked Questions

Can I use other berries instead of blueberries? Absolutely. Raspberries, blackberries, or a mix of all three work wonderfully in this recipe. Just keep the total quantity of fruit the same and toss them in flour before adding.

Can I freeze Mary Berry’s blueberry traybake? Yes, freeze it unglazed, well wrapped in clingfilm and foil, for up to 3 months. Defrost at room temperature and add the lemon glaze once fully thawed.

Why did my blueberries all sink to the bottom? This usually means the batter was too thin, or the blueberries weren’t coated in flour first. Both are easy fixes for next time, and trust me, there will be a next time.

Final Thoughts

Mary Berry’s blueberry traybake is the kind of recipe that earns a permanent spot in your baking rotation after the very first bake. It’s reliable, crowd-pleasing, and genuinely beautiful with that purple-studded top and lemon glaze finish. One bowl, one tin, zero drama.

Bake it for your next gathering and watch it disappear in minutes. Then quietly plan when you’re making the next batch for yourself.