Blueberry Crumble Cake with the Thermomix® comes with a hidden problem: the berries bleed. Frozen blueberries in particular release so much juice that the sponge underneath the crumble stays wet, and the crumble turns purple before it can crisp up. The trick we always use now: toss the berries in a tablespoon of flour before placing them on the sponge. The flour absorbs the first burst of juice during baking, and the crumble layer stays dry enough to turn golden.
The Thermomix® makes two batters one after the other in the same mixing bowl: first the sponge base, then the crumble straight after. Give the mixing bowl a quick rinse between the two steps. The recipe is for a 26 cm springform tin, 12 servings, and takes 55 minutes from start to oven finish.
Blueberry Crumble Cake with the Thermomix®
Ingredients 0 / 12 ✓
- 70 g sugar
- 1 sachet vanilla sugar
- 2 eggs
- 70 g butter plus a little extra for greasing the tin
- 180 g plain flour (type 405)
- 1 pinch salt
- 1 tsp baking powder
- 2 tbsp milk
- 500 g blueberries
- 100 g plain flour (type 405)
- 80 g sugar
- 80 g butter
Instructions 0 / 5
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1
Whisk until light and fluffy.
Add sugar, vanilla sugar and eggs to the mixing bowl and mix for 2 minutes / speed 4 until light and fluffy.
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2
Grease the tin.
Meanwhile, grease a springform tin with a little butter.
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3
Spread into the tin.
Add butter, flour, salt, baking powder and milk to the mixing bowl, mix for 20 seconds / speed 3 and spread evenly into the prepared tin.
Preheat the oven to 200 °C top and bottom heat.
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4
Prepare the blueberries.
Wash the blueberries, dry them well on a clean kitchen towel and spread them evenly over the sponge base.
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5
Make the crumble.
Add flour, sugar and butter to the mixing bowl, mix for 10 seconds / speed 4.5 to form crumble, then scatter over the blueberries. Bake the cake on the middle shelf for 35 to 40 minutes.
Tip: You can also grease the springform tin with homemade cake release paste made in the Thermomix®.
Serve the blueberry cake with freshly whipped Thermomix® cream!
Nutrition per serving
Fresh vs frozen: what actually works
With fresh blueberries the bleeding is manageable, as long as you pat them dry thoroughly before placing them on the sponge. Frozen berries straight from the freezer are considerably riskier: they thaw in the oven and release far more liquid than fresh ones in a short time, giving the sponge below no chance to set. We have made this recipe with both options. The result with frozen berries was always a little moister, but perfectly good to eat. The flour trick helps in both cases, but with frozen berries it is essential.
Anyone using frozen berries should also set the baking time towards the upper end. With fresh blueberries, 35 minutes at 200 °C top and bottom heat is enough. With frozen ones, go for the full 40 minutes, and check in the last 5 minutes whether the crumble is starting to turn golden brown.
The crumble step: the time limit is no joke
Flour, sugar and butter go into the mixing bowl for the crumble and are mixed for 10 seconds at speed 4.5. That time limit is serious. At 12 to 15 seconds the mixture clumps together into one mass and you no longer have crumble, but a second layer of dough. We watch through the lid while mixing: as soon as coarse, irregular crumbs are visible, stop. Coarse is correct. Evenly fine crumble goes flat in the oven and loses its texture.
The butter for the crumble should be cold, not at room temperature. Cold butter stays crumbly during the blending process, while soft room-temperature butter combines too quickly with the flour and sugar. The sponge step before uses soft butter in the Thermomix®, so for the crumble: take fresh butter straight from the fridge.
What the mixing bowl needs between the two batters
After the sponge step (2 min / speed 4 for the egg and sugar mixture, then 20 sec / speed 3 with butter, flour, salt, baking powder and milk), batter sticks to the base and the blade unit. Give it a quick rinse and a quick wipe. The mixing bowl does not need to be spotless, but if larger damp pieces of batter remain inside and you then add the dry crumble butter and flour mixture, those residues will bind the crumble together before the mixing even starts.
Freezing: what works and what does not
The fully baked and completely cooled cake can be frozen. Wrap it in aluminium foil, then place in a freezer bag, for up to 3 months. To defrost, leave it at room temperature, not in the microwave, as the crumble will turn chewy. Stored in the fridge the cake keeps for 2 to 3 days, though the crumble loses its texture faster in the fridge than at room temperature under a cloth.
For anyone who bakes with crumble and fruit regularly: on mixmyday.com there is also a crumble sheet cake without yeast that needs no springform tin and stays moist with a cream topping added straight after baking. For a basic crumble recipe (suitable for batch-making and freezing), the crumble basic recipe with the Thermomix® is worth a look. Anyone who wants to serve the cake with freshly whipped cream will find a guide for whipping cream with the Thermomix® on mixmyday.com.
When to buy blueberries and what to use in winter
Goes well with: vanilla ice cream and vanilla sauce.
Also good: cookie cups with chocolate cream.
Domestic blueberries are in season from the beginning of July to the end of September. In this window the cake is at its most flavourful made with fresh berries from the market or a farm shop. We buy 2 to 3 kilos at a time during peak season, spread some out flat on a baking tray, pre-freeze them individually, then transfer them into freezer bags. This gives us separate berries all year round that do not freeze into a clump and thaw in a controlled way during baking. Outside of season, cultivated blueberries from the supermarket are an option, though they taste noticeably paler. Frozen berries from your own summer harvest usually beat them by far.
