Nutella for Grown Ups & the Pistachio White Chocolate Mousse Cake

I was given Carole Bloom's The Essential Baker: the Comprehensive Guide to Chocolate, Fruit, Nuts, Spices, and Other Ingredients as a Christmas gift about two years back and it has received a lot of love in our household. Bloom's precise and carefully composed recipes not only deliver fabulous results, but provide some fine foundations for further baking experimentation. One case in point is this scrumptious hazelnut cake which I later used as the base for a pistachio and white chocolate mousse cake. I'm going to post her basic recipe here, followed by my variation.

1. Bloom calls for 2 & 1/4 cups hazelnuts which you toast and then rub in a towel to remove the skins.
2. The next ingredient is 1/2 cup light cooking oil. I used canola as a tribute to my Albertan heritage. You blend the nuts with the oil until they make a very fine slurry in a food processor. This takes a couple of minutes.
3. Melt 9 oz bittersweet and 7 oz milk chocolate in the microwave, or in a double boiler if you like to fiddle with that kind of nonsense. Add this mixture to the food processor and blend again until fully mixed. I've found that Ghiardelli is perfectly suitable for this cake.
4. Beat 6 extra large eggs until they are frothy, and then slowly add 1/2 cup of sugar. Beat in total about five minutes on high until the egg mixture is very thick and pale. At this point, add the chocolate mixture. She suggests beating, but I mix it in with a spatula.
5. Whip a cup of heavy cream until quite thick. Mix this into the above mixture with a spatula.
6. Pour into a prepared baking pan and bake in a bain marie for one hour at 350 f. Turn the oven off and allow the mousse cake to stand for 15 minutes in the oven before you remove it.

The pistachio variation calls for a few simple substitutions. First, substitute pistachios for the hazelnuts. Replace the chocolates with 1# white chocolate, and then blend the whole eggs with a couple of tablespoons of sugar rather than the 1/2 cup. Otherwise, follow her instructions to the letter.

The Gianduia mousse cake is reminiscent of Nutella, but all grown up. Another variation I've tried was adding a shot of Cointreau and some orange zest, although the basic cake is so delicately perfect that it's almost a shame to spruce it up. The pistachio variation is kind of sweet, and a lovely pale green in color. I served it up as a birthday cake, and to celebrate a friend's bon voyage to the Amazonian rain forest. They seemed pleased.