For the cake
- 110g softened unsalted butter
- 120ml sunflower oil
- 5 eggs
- 1tbsp vanilla extract
- 250ml milk
- 450g white caster sugar
- 350g plain flour
- 1tsp baking powder
- 1tsp table salt
- 3tbsp rainbow sugar strand sprinkles (vermicelli)
For the frosting
- 330g softened unsalted butter
- 1 pinch table salt
- 210g rainbow sugar strand sprinkles (vermicelli)
- 2tsp vanilla extract
- 60ml single cream
- 400g icing sugar
- Preheat the oven to 180C/350F/Gas Mark 4. Grease and line 3 x 20cm cake tins.
- Beat 110g unsalted butter with the oil and sugar with an electric mixer until it is light and fluffy. Continuing to mix on high, add each egg one at a time before pouring in the 1tbsp of vanilla extract.
- In a separate bowl, sift together the flour, salt and baking powder. Using a large metal spoon, fold the flour mix into the liquid batter – making sure that there are no small clumps of flour that are not incorporated. When the mix is ready, fold through the 3 tbsp of rainbow sprinkles with three or four folds – if you overmix the sprinkles at this point you risk the colours bleeding into the batter and making a mush.
- Share the batter equally between the three tins and bake in the preheated oven (ideally on the same shelf) for around 35 minutes. Test with a skewer at the end of cooking to make sure that the batter is fully cooked – the cake should be golden and springy to tough, while a skewer should come out clean when inserted into the middle.
- Allow the cakes to cool in their tins for 5-10 minutes before carefully removing and leaving to cool fully on a rack.
- To make the frosting, beat the 330g of unsalted butter with the pinch of salt in a freestanding electric mixer until it is light and fluffy. You will notice the colour of the butter changes, going from a creamy yellow to an almost white as it fluffs up. Be sure to scrape down the sides of the mixer periodically to get everything whipped up.
- Gradually add the icing sugar in three of four stages, beating on high to incorporate everything before adding more icing sugar. Keep scraping down the sides every so often before beating some more on a high setting. This stage will take about 5 minutes so please be patient.
- When everything is light and fluffy, beat in the vanilla extract and gradually add the single cream. You should be left with a light, pillowy cloud of frosting at this stage.
- Use approximately 1/3 of the frosting to sandwich the three cakes together. I like to rest the cake in the fridge for around 30 minutes at this stage to help the cakes firm up together with the frosting.
- Remove from the fridge and use the rest of the frosting to spread an even layer all over the cake – starting from the top and working down the sides. A pallet knife will be your friend at this point to get a sharp, crisp finish. Sometimes I do this in two stages – returning the cake to the fridge in between applying two coats of frosting to firm up slightly.
- Once the final layer of frosting has been applied, you can do the fun bit with the rainbow sprinkles. Gently scatter them all over, using your hands to gently pat them into the frosting to get an even spread all over. Decorate with candles and indoor sparklers before conveying to the birthday person with a rousing chorus of Happy Birthday!
- Category: Baking, Cake, Birthday Cake
- Cuisine: American
Keywords: American, Baking, Birthday Cake, Cake