Description
The Mary Berry Rainbow Cake is a multi-layered sponge cake where each layer is tinted a different color of the rainbow. Sandwiched with a light, sweet buttercream and covered in a smooth vanilla frosting, it’s both a visual treat and a delicious dessert. Mary Berry’s version focuses on a tender sponge, even layers, and a buttercream that’s light and not overly sweet—making the cake as enjoyable to eat as it is to look at.
Ingredients
For the Cake Batter (makes six 8-inch layers):
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Unsalted butter – 375g (softened)
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Caster sugar – 375g
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Self-raising flour – 375g
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Baking powder – 1½ teaspoons
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Eggs – 6 large
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Milk – 4 tablespoons
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Vanilla extract – 2 teaspoons
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Gel food coloring – red, orange, yellow, green, blue, purple (use gel for vibrant color)
For the Buttercream Frosting:
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Unsalted butter – 250g (softened)
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Icing sugar – 500g (sifted)
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Vanilla extract – 1 teaspoon
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Milk – 2–3 tablespoons (as needed for consistency)
Instructions
Step 1: Prepare the Oven and Tins
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Preheat oven to 180°C (160°C fan) or 350°F.
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Grease and line 6 cake tins (or bake in batches if you have fewer tins).
Step 2: Make the Cake Batter
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Cream butter and sugar: Beat until pale and fluffy.
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Add eggs: One at a time, beating well after each.
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Stir in vanilla and milk.
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Fold in sifted flour and baking powder: Mix until just combined.
Step 3: Divide and Color the Batter
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Divide batter evenly into 6 bowls.
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Add a small amount of gel food coloring to each bowl. Stir gently to combine. Use enough to get bold colors.
Step 4: Bake the Layers
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Spoon each colored batter into a separate tin.
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Bake for 15–18 minutes or until a skewer comes out clean.
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Cool in tins for 5 minutes, then turn onto racks. Let cool completely.
Step 5: Make the Buttercream
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Beat butter until smooth.
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Gradually add icing sugar: Beat until light and fluffy.
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Add vanilla and milk as needed for spreadable consistency.
Step 6: Assemble the Cake
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Place the purple layer on your cake board or plate.
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Spread a thin layer of buttercream.
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Repeat layering in this order: purple, blue, green, yellow, orange, red—adding buttercream between each.
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Cover the entire cake with a thin crumb coat of buttercream. Chill for 15–20 minutes.
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Frost the outside of the cake smoothly using the remaining buttercream.
Step 7: Decorate and Serve
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Optional: Add sprinkles, piped decorations, or a colored drip.
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Slice to reveal the rainbow inside!