Blackberry crumble traybake

Portion size: Serves 12
Prep time 40 min. Cook time 55 min
Difficulty: easy

Freezable

Vegetarian

Emily Gussin

Food producer and sustainability lead, delicious.

Save

Crumble meets cake in this easy blackberry traybake with an oaty streusel topping.

Why it’s so good: This cosy traybake is a great way to use up a glut of blackberries. Part crumble, part cake, it’s the perfect treat for the end of summer. Serve it with the optional custard for a filling pudding.
Make ahead: Both the cake and the custard can be enjoyed warm or made ahead to eat later. Keep the cake in a sealed container at room temperature (unless it’s very hot weather, in which case the fridge will preserve the fruit in the cake longer), but keep the custard in the fridge once cooled. You can heat the custard again gently to eat warm with the room temperature cake later or enjoy it cold from the fridge. You could also freeze the cake in portions and defrost at room temperature.
Easy swap: If you don’t fancy making the custard too, you could simply warm through bought custard in a pan with a sprig of rosemary. Remove from the heat, cover with a lid and leave to infuse for 30 minutes to impart a subtle rosemary taste.

There’s a pud for all seasons, including summer strawberry and autumnal apple, in our complete crumble recipes collection.

Join Extradelicious to unlock Cook Mode

Ingredients

120ml sunflower oil, plus extra for greasing
140g self-raising flour
100g golden caster sugar
½ tsp bicarbonate of soda
¼ tsp fine sea salt
1 medium egg
100ml whole milk
1 tsp vanilla extract
Finely grated zest and juice ½ lemon

For the streusel topping

100g self-raising flour
80g porridge oats
50g demerara sugar
Finely grated zest ½ lemon
90g unsalted butter, chilled and chopped
450g blackberries

For the rosemary custard

200ml whole milk
300ml double cream
2 rosemary sprigs
3 medium egg yolks
50g golden caster sugar

Specialist kit

Baking tin around 22cm x 30cm

Useful to have

Probe thermometer

Join Extradelicious to unlock Cook Mode

Method

Heat the oven to 180C/160°C fan/gas 4, then grease the cake tin with oil and line with baking paper. Make the streusel topping first. Stir together the 100g flour, oats, demerara sugar and lemon zest in a large bowl. Rub in the butter until you have lots of sticky clumps (don’t go as far as you would with a crumble). Set aside.
Combine the 140g flour, sugar, bicarbonate of soda and salt in a large mixing bowl. In a jug, whisk the oil and egg until combined, then whisk in the milk, vanilla and lemon zest. Pour the wet ingredients into the dry and stir to combine. Gently stir in the lemon juice. Tip the batter into the prepared tin.
Scatter half the streusel mixture evenly over the cake, then top with the blackberries. Finish with the remaining streusel mixture. Bake for 35-40 minutes until a skewer pushed into the centre comes out with only a few damp crumbs.
Recipe continues after advertising adslot-recipe-4
While the cake bakes, make the rosemary custard. Put the milk, cream and rosemary in a saucepan over a medium heat and warm through, stirring regularly to stop it catching. Meanwhile, in a large bowl, use a balloon whisk to beat the egg yolks and sugar together until combined and a little paler. Once the milk is steaming hot and quivering (but not quite boiling), gradually pour the milk mixture into the egg mixture, whisking constantly until everything is combined.
Pour the mixture back into the pan and put over a low-medium heat. Use a rubber spatula to gently stir the mixture as it heats through (you don’t want to add air bubbles at this point). Cook gently until the custard thickens enough to coat the spatula (about 5-7 minutes). It should reach 82°C when it’s ready but you can just check by dunking the spatula in the custard, then pushing your finger through it – if the line you’ve created in the custard holds for a few seconds it’s ready. Remove the rosemary and serve the custard hot or allow to cool.
Leave the cake to cool in the tin for about 10 minutes before transferring to a board to slice and serve warm with the hot custard. Or transfer to a wire rack and leave to cool completely.