White Cake with White Chocolate Buttercream

I absolutely love the Magnolia Bakery cookery book. Never mind that I can't work out the measurements which are all in American. Actually most of this was solved for me by a gift from a friend - two fridge magnets, one with a set of US-UK liquid conversions, and the other for solids. Yay. I am sorted. The Magnolia Bakery cookery book contains some of the most indulgent cakes I have ever baked, and I have baked a fair few. In fact, though I can't rival the Great British Bake Off for consistency I could run rings around the lot of them in sheer volume. To give you an idea, at home my family, and there are only four of us in total, are chomping our way through chocolate whoopie pies, a white chocolate cheesecake dotted with raspberries, and a white cake with white chocolate buttercream icing. Why is it called white cake, one of my kids asks. It's so obviously white that its name seems like a let down. It's not a let down, I explain. It is understatement. The Magnolia Bakery's white cake is a huge effort. It involves ages and ages of whisking and electric mixing to get exactly the right ratio of air bubbles to mixture. Whisked egg white has to be combined exactly right so that when the two sponge cakes rise, they are light and frothy. But the true seriousness of the task lies in the buttercream. And what a heart stopper it is. Three bars of white chocolate and two whole packs of butter, whisked and whisked and whisked, with vanilla essence and a pack of icing sugar, slathered over one cake base, plonk the other one on top, and then slather again. This cake is so rich that, with one slice down you, it's no food for a week as your body recovers from the shock. It is the attrition of all foods. It is, therefore, the perfect special occasion cake. In the past month I have celebrated two 50th birthdays of people I love, and have made this cake both times, covering it with gold glitter to symbolise 50 years. Actually what it did was to give the cake a distinctly 70s, camp, Abba look. It's so shimmery!  Only to be eaten wearing platform leather boots and flares. But I also made it for a 10th birthday decorated with delicate violet flowers, and I made it for the sheer hell of it one Sunday and covered it with chocolate buttons. White cake. It is baking's blank canvas. Go buy the book.