From the second you slice into the cake with your fork, you know you're in for a whirlwind of textures, from crispy to silky and crunchy to crumbly. Plus each layer is flavored with restraint so that there's no specific dominating flavor; instead, there's a general sense of nuttiness from the pistachios and a mild sweetness from the white chocolate. Part of the fun when devouring it is to eat all of the layers together and then alternate between eating only two or three of the layers to experience each of the flavors and textures differently.
The Ellen Diagram
Helpful diagrams of Alliance's entremets are hung on the walls of the bakery. The Ellen starts with a very thin layer of pistachio almond cake. The next layer (the best layer) is a crispy, crunchy layer of hazelnut praline. A light, silky pistachio cinnamon mousse is next, followed by a paper-thin slice of cinnamon white chocolate. Three columns of white chocolate mousse are piped atop that plaquette, and another plaquette is added as a finishing touch.
The Base Layers
Brad already had the two bottom layers laid out and in the freezer. These are frozen to make sure the pistachio mousse layer is clearly delineated from the hazelnut praline layer.
Pure ground pistachios are added to both the pistachio almond cake layer and the pistachio mousse layer. Add a little salt to this and you'd have a great pistachio butter.
These wafers are what give the hazelnut praline layer its unique crispiness. That layer is what elevates a delicious pistachio cake to a delicious and texturally interesting pistachio cake.
Brad starts the pistachio cinnamon mousse layer by steeping both ground cinnamon and whole sticks of cinnamon in heated milk.
Since some of the moisture steams out of the milk as it's heating, Brad carefully adds more milk to bring the mixture back up to its original weight.
After fishing out the cinnamon sticks, Brad whisks eggs with sugar and corn starch and then adds the mixture to the steeped milk.
In order to skip tempering the eggs (a somewhat time-consuming process that ensures no clumps of cooked egg mar the texture of the final mousse) the mixture is blended with a immersion blender, which mixes and smooths out any lumps.
Soft butter is whisked into the thickened mixture.
Green Food Coloring
Since the color of the pistachio paste is a less-than-desirable brown, Brad adds a little green food coloring. "Don't worry," he added, if I thought it looked a little too green. Whipped cream still had to be added, which would dilute the color a bit.
Brad carefully and quickly folds in freshly whipped cream.
The more palatably green mousse is then spread over the praline layer.
After the three bottom layers take another freezer vacation, Brad slices them into bars and places a plaquette of cinnamon-laced white chocolate on top of the pistachio cinnamon mousse.
White Chocolate Mousse
Three columns of white chocolate mousse are piped out on top of the plaquette.
Brad heats a knife with a blow torch to clean up the edges of the piped mousse.
The resulting bar of cake is impressively neat and symmetrical.