Fanta tray bake is one of the few sheet cakes where the lemonade does real work in the batter. The carbonation expands the gas bubbles created by the baking powder as the cake bakes, and the citric acid from the orange adds further lift. The result is a sponge that stays remarkably light for a tray format, even after two hours in the fridge. We bake the base in 25 minutes at 175 °C, then the fridge does the rest.
Fanta Cake with the Thermomix®
Ingredients 0 / 12 ✓
- 5 eggs
- 170 g sugar
- 1 sachet vanilla sugar
- 330 g plain flour (type 405)
- 1 sachet baking powder
- 100 g oil
- 200 g Fanta or other orange lemonade
- 175 g tinned mandarin oranges drained
- 500 g double cream
- 2 sachets cream stabiliser
- 600 g soured cream
- 40 g sugar
Instructions 0 / 8
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1
Whip until fluffy.
Insert the butterfly whisk, add eggs with sugar and vanilla sugar to the mixing bowl and whip for 4 minutes / speed 4 until light and fluffy.
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2
Preheat the oven.
Preheat the oven to 175 °C top and bottom heat. Line a baking tray with baking paper.
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3
Mix the batter.
Add flour, baking powder and oil and mix for 20 seconds / speed 3. Add Fanta and fold in for 10 seconds / speed 3.
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4
Bake the sponge.
Spread the batter onto the baking tray and bake for 20 to 25 minutes on the middle shelf of the oven. Remove the cake from the oven and leave to cool. Rinse the mixing bowl.
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5
Drain the oranges.
Tip the mandarin oranges into a sieve and leave to drain.
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6
Whip the cream.
Insert the butterfly whisk into the mixing bowl. Whip the cream with the cream stabiliser at speed 3.5, watching closely, until stiff, then set aside.
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7
Mix the cream topping.
Remove the butterfly whisk, add soured cream with sugar to the mixing bowl and mix for 10 seconds / speed 3.
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8
Chill.
Add the mandarin oranges and whipped cream and fold in with the spatula. Spread the cream evenly over the base and refrigerate for at least 1 hour.
Tip: The cake is also very good without the topping. Bake the base, spread it with a simple icing and sprinkle with sugar pearls of your choice. That way the cake can easily be eaten by hand as well.
Video
Nutrition per serving
What Fanta actually does in the batter
If you think of Fanta as just a flavouring, you are missing the physics. Carbonation is dissolved CO2 under pressure. The moment you fold it into the batter, the gas starts to escape and form air pockets. The oven then expands those pockets before the batter sets. At the same time, orange lemonade is mildly acidic. That acid reacts with the sodium bicarbonate in the baking powder and releases additional CO2, the same principle as buttermilk or yoghurt in other sponge batters.
The result is a double rise that you simply do not get with a standard sponge made with water. That is why we recommend adding the Fanta right at the end at speed 3 and mixing for only 10 seconds. Longer mixing drives the carbonation out before it can do its job.
The soured cream topping: why the order matters
The topping has two separate stages in the Thermomix®, and the separation is not accidental. First you whip the cream at speed 3.5 until stiff, watching closely, then set it aside. Only then does the soured cream go in with the sugar for 10 seconds at speed 3. If you were to whip the soured cream and cream together, the fat in the soured cream risks causing the cream to collapse again. Prepare both separately, then fold together by hand with the spatula.
The mandarins must be well drained. Wet tinned fruit will make the topping runny within an hour. Use a sieve, drain thoroughly, and that is all there is to it. If you prefer not to use mandarins, tinned peach halves work just as well, also well drained and cut into smaller pieces.
Chilling time and storage
The cake needs at least one hour in the fridge for the topping to set firmly enough to slice. Two hours is better. A baking tray with a lid is handy so the topping does not pick up fridge odours. The finished cake keeps for 3 to 4 days in the fridge. You can freeze the base on its own very well, but always make the topping fresh.
If you want to bake the base without a topping, spread it with a simple icing similar to a red wine cake and scatter sugar pearls over it. That is the quicker option for cake buffets where there is no fridge nearby. For more moist tray bakes with a special ingredient, the advocaat marble cake works on exactly the same logic, where an unexpected liquid changes the batter in a way that plain water never could.
More tray bakes, sponge cakes and meringues can be found in the Mix Baking Book for the Thermomix®.
Why our recipe differs from the typical blog versions
Most Fanta cake recipes online use 250 to 300 g of sugar in the batter and a whole large tin of mandarins, often 350 g or more. We deliberately use 170 g of sugar and only 175 g of drained mandarins. The reasoning is straightforward: Fanta already brings a lot of sweetness to the batter, and the soured cream topping adds another rich, creamy layer on top. With the usual amount of sugar the whole thing becomes too sweet, and with too many mandarins the topping runs. Our 200 g of Fanta to 330 g of flour gives a batter that stays light without becoming soggy, and the smaller amount of mandarins keeps the topping firm enough to slice cleanly, even on the second day.
Goes well with: vanilla ice cream and coffee.
