I love birthdays. More than Christmas, more than weddings, more than any other celebrations. And I love them even more since I have become a mother, because my daughter’s birthday is not only her special day to celebrate, it is also my birthday as a mom.
Finally, my daughter has turned three. Whoever has children will understand the suffered and intense meaning of the word “finally”. So, she had her first “real” birthday party, with friends, whom she chose, balloons, lots of food (I might be a strange sort of Italian, but still Italian after all) and a cake. Actually THE cake.
I have been “flirting” with the idea of a rainbow cake for ages but I was never able to find the right occasion because, let’s face it, unless one is used to hang out in Liberace-inspired extravanganzas, or to party in carnival of Rio style, it’s really unlikely to find the right moment to make something so over the top.
But a kid’s birthday party, well, that’s whole another story. It was so nice to see their surprised faces once the cake was cut open, and to see them “fighting” over the piece of cake with their favourite colour, my daughter even learnt about indigo! It was lot of work, seven layers of cake all coloured and baked individually, but in the end it was well worthy. My husband said that next time each individual sponge should be flavoured individually with a taste inspired by the respective colour. OK it was fun, OK it was worthwhile, but he still doesn’t know that there might not be a next time!
For the sponge:
500gr caster sugar
400gr plain flour
100gr corn flour
3 heaped tsp of baking powder
Gel food colouring
For the filling milk cream:
400ml full fat milk
10gr ground cardamom
40gr plain flour
40gr corn flour
80gr caster sugar
150gr double cream
100gr white chocolate
For the Buttercream:
400gr of granulated or caster sugar
80ml of water (for precise measurement weight it on a digital scale: 80gr is 80ml)
5 large egg whites
1 tsp of cream of tartar or lemon juice
680gr of butter at room temperature
2 tbsp of vanilla paste
This recipe is very much a joint effort among me, my cooking books, and my very good friend Francesca. She gave me the recipe for the milk cream filling, which I have adapted by adding a Finnish touch of cardamom and the white chocolate.
Prepare the sponge. Cream the butter and the sugar, mix the powders and add to the butter and sugar mix alternating with the eggs, keep mixing until all the ingredients are well incorporated. The batter should be enough to make 7 batches of 270-280gr each, divide them as evenly as possible using a scale and add the food coloring accordingly to get the seven colours of the rainbow. Bake each batch in a round 20-24cm tin for 15 minutes at 180°C. Place on a cooling rack.
For the milk white chocolate and cardamom filling cream, warm 300ml of milk in a saucepan with the cardamom and the sugar, dissolve the flours in the remaining milk and add to the saucepan. Add the honey and keep mixing, bring gently to the boil and let thicken while mixing for a few minutes. Remove from the heat and melt the white chocolate inside the milk sauce. Pour in a bowl, cover with cling film and let it cool thoroughly in the fridge. Whip the double cream and combine gently with the milk and chocolate cream.
Combine sugar and water in a small saucepan over medium-high heat. Cook the mixture until it reaches 120°C. Meanwhile combine the egg whites with the cream of tartar and whisk to a soft peak. As soon as the syrup reaches 120°C, reduce the whisk speed to medium and start pouring, slowly but steadily the hot syrup into the eggs. Careful to not splash the hot syrup! Raise the speed to high and continue to whisk until the mixture has cooled down to almost at room temperature. It could take a little while, sometimes I help the process by placing ice-bags in contact with the outer walls of the mixing bowl. When the meringue is not more than lukewarm reduce the speed of the mixer and start adding the butter, one spoon at once and making sure the previous is properly mixed before adding the next one. If butter seems to not incorporate properly you can raise the speed of the mixer just make sure to not over-mix or it will split. Once incorporated all the butter add the vanilla paste.
Build the cake by alternating one layer of cake with a couple of spoon of milk cream filling. Soak the sponge with a syrup made with equal amount of orange juice freshly squeezed and icing sugar. Cover the cake with a thin layer of buttercream and use the rest to decorate with a piping bag or just a palette knife according to your taste and inspiration.