For the elderchild's birthday, I wanted to make something very different. We'd been talking a lot about all the interesting mushrooms that had been cropping up as the weather cooled and I was reminded of making meringue mushrooms in culinary school and how fun that was. So I set about thinking of a project that would highlight mushrooms and yet still be an appropriate autumn themed birthday cake.
I hit upon a Buche d'Automne.
First, I made the mushroom parts first with a simple Italian meringue and let them sit in a cooling oven overnight. The stems and shelf mushrooms were white and then I added some brown food coloring to make the tops.
The next day I made the pumpkin pastry cream, by adding pumpkin purée to a pastry cream recipe and then mixing in cinnamon, clove, allspice, ginger and nutmeg. That was kept chilled until it was time to assemble the cake.
A day later I made a joconde - a sponge cake with almond flour, cooked in a very thin layer in a sheet pan. This was then soaked with a ginger simple syrup. To make a pumpkin mousseline, I whisked the pumpkin pastry cream and then folded in whipped cream. This was spread over the joconde and then it was rolled and chilled. I also hand painted sugar paper with food coloring and cut out oak and maple leaves.
Finally, on the big day, I made a maple Italian meringue by substituting maple sugar for white sugar. I frosted the rolled cake with the meringue, used a torch to make it look more like a birch log, and then decorated the cake with the mushrooms, leaves and some fresh daisies.
