Donal's Family Kitchen

Perfect Birthday Funfetti Cake

Name: Perfect Birthday Funfetti Cake
Total time: 65 min
Yield: 20 servings
Ingredients: 400g unsalted butter, softened; 350g caster (superfine) sugar; 6 large eggs; 2 tsp vanilla bean paste; 430g plain (all-purpose) flour; 1 tsp baking powder; 300ml buttermilk or natural yoghurt; 80g large sugar sprinkles (about 10 tbsp); For the icing:; 200g unsalted butter, softened; 300g icing (confectioner's) sugar; 2 tsp vanilla bean paste; Pink food colouring; 1-2 tbsp just-boiled water; Sprinkles, to decorate; Utensils:; KitchenAid mixer; Baking Tray; Skewer; Large bowl for icing; Spatula; Handmixer

It might seem weird to add boiling water to icing but trust me, it makes for the smoothest, fluffiest icing imaginable. Once you try this method you won't come back.

Donal SkehanFrom the series · Donal's Family Kitchen

65 min totalServes 20Medium

Time65 min

Serves20

SkillMedium

ShowSuper Food In Minutes

Method

Preheat the oven to 200°C/180°C fan/400F/Gas 6 and grease and line a 33 x 23cm (13 x 9in) baking tray or cake tin.

Cream the butter and sugar together until light and fluffy. Gradually add the eggs and vanilla bean paste, mixing well between each addition.

Gently fold in one-third of the flour, the baking powder and one-third of the buttermilk or yoghurt; repeat until you have added all of the flour and buttermilk.

Bake for 50 minutes until risen and lightly golden and a skewer inserted in the centre comes out clean (this step is very important as ovens can vary). Cool in the tin for 5-10 minutes, then turn out onto a wire rack to cool completely.

Meanwhile, make the icing. Beat the butter until light and fluffy then gradually beat in the icing sugar until you have a smooth icing. Add the vanilla bean paste, food colouring and 1-2 tablespoons of just-boiled water. Whisk together to make a bright, smooth icing.

Once the cake is cool, transfer to a serving plate or board. Spread the icing all over the cake with a swirly pattern then scatter with the sprinkles and serve.

Cook's notes

Fold the sprinkles through at the very end and work gently — over-mixing or a warm batter makes the colours bleed and you lose the confetti effect.
Add the eggs gradually and beat well between each; if the mixture looks like it's splitting, a spoonful of the measured flour brings it straight back.
The skewer test matters here — ovens vary and a 33 x 23cm tin is deep, so check at 45 minutes and give it the full 50 if there's any wet crumb clinging.
Let the cake cool completely before icing, otherwise the buttercream slides straight off. Add the just-boiled water a little at a time until the icing is soft enough to swirl but still holds its shape.

Serve with It needs nothing more than candles and a pot of tea, though a scoop of vanilla ice cream turns a slice into pudding. For a party, cut it into small squares so it stretches across a big table of children.

Make ahead & storage Keep it in an airtight tin at room temperature for up to four days — the buttermilk sponge actually improves on day two. Uniced sponge freezes well wrapped tightly for up to a month.

Recipe by Donal Skehan · From the series Donal's Family Kitchen · Photography © Appetite Media
Published 13 July 2026 · Updated 15 July 2026

Nutrition

Per serving · estimated

469kcal

5gprotein

54gcarbs

26gfat

Approximate — calculated from the ingredient list using USDA food data. A guide, not a medical figure.

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