Some of these taste tests – for instance, the oven chips one from last summer – surprise me with their overall quality and minimal processing. But others, such as today’s party cakes, sit firmly in the ultra-processed category, and often make contradictory claims, “handmade” and “carefully selected high-quality ingredients” being just two.
I want my children to enjoy treats without food anxiety, but we also owe it both to ourselves and to them to know what we’re actually eating. Unusually, the price of today’s cakes didn’t reflect processing levels. While more expensive products are often less processed, even the premium cakes included an array of emulsifiers (including mono- and diglycerides of fatty acids, polyglycerol esters and sodium stearoyl-2-lactylate), preservatives, stabilisers, synthetic raising agents such as diphosphates, and glucose-fructose syrup, a heavily processed industrial sweetener linked to metabolic concerns. I’ve listed the number of additives in each product, excluding natural colours and flavourings, pectin, citric acid, carbonates and bicarbonate of soda, beeswax and glucose syrup. I also scored the cakes based on their appearance, taste, texture, value, certifications, animal welfare considerations and total sugar content (which varied greatly).
The best supermarket party cakes
Best overall:
Waitrose over the rainbow cake
★★★★☆
A deep, 15cm-diameter, 9cm-high, light-purple, orange and yellow layered rainbow cake covered in sprinkles with a pretty piped icing edge. A delicious vanilla buttercream made with real vanilla extract, a soft and moist sponge and, despite tasting sweet, fewer total sugars than most (39.2%). Contains eight additives, including four emulsifiers, and glucose-fructose syrup. Made with free-range eggs and unsalted butter, and palm oil-free.
Best bargain:
The Bakery at Asda rainbow jazzie cake
★★☆☆☆
A huge rainbow cake (with magenta, yellow and carrot-coloured layers) covered in sprinkles. A fluffy, moist sponge and a classic sweet icing that’s a touch greasy, flavourless and bland (and ergo kid-friendly). Fewer additives than most (six, including palm oil and carminic acid, a red colouring made from cochineal) and, at 33%, the least total sugars in the test. Not suitable for vegetarians.
And the rest …
M&S rainbow layer cake
★★★★☆
One of the tallest cakes in the test, with five tiers of light, pastel-coloured sponge covered generously with a silky, Madagascan vanilla buttercream. Piped buttercream on top and sprinkles on the sides. Very sweet (41.6%), but only five additives (and no palm oil, preservative or glucose-fructose syrup), which help make this my best splurge.
Lola’s vanilla layer cake
★★★☆☆
A very elegant vanilla sponge with a delicate buttercream icing and multicoloured pearl sprinkles. A delicious compote centre that’s tart, full of flavour and a respite from the uber-sweet buttercream (43.4% total sugars). Made with real butter, double cream and soured cream, as well as 12 additives, including palm oil, titanium dioxide – which has been banned in the EU since 2022 – and propylene glycol.
Fiona Cairns mini pink boutique cake
★★★☆☆
An elegant, moist sponge sandwich with a fine crumb, thick icing, delicate vanilla buttercream and a few sprinkles, as well as a refreshing blob of raspberry jam. Made with butter and free-range egg, but still contains 10 additives and, at 44% total sugars, the sweetest cake in the test.
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Sainsbury’s Taste the Difference rainbow layer cake
★★★☆☆
A tall, 14cm-diameter and 9cm-high, pink, yellow, carrot and deep-purple rainbow cake with sprinkles on the sides and plain icing on top. A moist, light sponge, and a thin layer of buttery icing with a balanced vanilla flavour. Very sweet (42.1% sugar) and six additives, including palm oil and palm stearin.
Lidl Rowan Hill Bakery madeira party cake
★★☆☆☆
A large, 20cm-wide Victoria sandwich filled with jam, with naked sides and frosting and sprinkles on top. A strong value option, though it does contain eight additives (including two emulsifiers, glucose-fructose syrup and palm oil) and 40.3% total sugars.
Tesco vanilla party cake
★★☆☆☆
A large, classic, light Victoria sponge with a lovely, fruity raspberry jam centre. Topped with a bland but firm icing and a dusting of sprinkles, very sweet (42.4% total sugars), and has all of 10 additives, including three emulsifiers, glucose-fructose syrup and two palm products.
Morrisons sprinkle cake
★★☆☆☆
A four-layer sponge with apple and raspberry jam layers. Covered with icing, with more piped on top and sprinkles all around. The delicious sour jam is a welcome break from the very sweet, fondant-like icing (total sugars: 42.5%). Contains nine additives, including two emulsifiers, glucose-fructose syrup and palm oil.
Aldi Village Bakery party cupcake platter
★☆☆☆☆
Colourful cupcakes, including vanilla and chocolate sponge, all topped with a generous swirl of frosting and filled with jam or Rainforest Alliance-certified chocolate. A soft and moist sponge, but the icing has a smooth, synthetic, gummy texture. Contains 10 additives, including three emulsifiers, palm oil and palm fat, and 41.6% total sugars.
For more, read 14 pieces of baking kit the pros can’t live without
