- 5 ounces (about one heaping cup) hazelnuts, blanched to remove dark skins*
1/2 pound unsalted butter (plus 1 tablespoon melted extra for greasing the pan)
1/2 vanilla bean
1 1/3 cups powdered sugar, plus extra for dusting the cake
1/3 cup all-purpose flour
5 extra-large egg whites (I used 6 since I was using large eggs)
3 tablespoons granulated sugar
|Preheat oven to 350deg.|
Spread the blanched hazelnuts on a baking sheet, and toast 12 to 15 minutes, until they're golden brown and smell nutty. Let them cool.
Cut out a circle of parchment paper to fit in the bottom of a 10-inch round cake pan. Brush the pan with a little melted butter and line the bottom with the paper.
Place the rest of the butter in a medium saucepan. Slice the vanilla bean lengthwise down the center, and using a paring knife to scrape the seeds and pulp onto the butter. Add the vanilla pod to the pan, and cook the butter until the butter browns and smells nutty (about 6 to 8 minutes). It helps to frequently scrape the solids off the bottom of the pan in the last couple minutes to ensure even browning. Set aside to cool. Remove the vanilla pod and discard.
Grind the hazelnuts with the confectioners' sugar in a food processor until they're finely ground. Add the flour and pulse to combine. Transfer to a large bowl.
Place the egg whites in the bowl of a stand mixer fitted with the whisk attachment. Add the granulated sugar and mix on high speed 4 to 5 minutes, until the mixture forms very stiff peaks. When you turn the whisk upside down, the peaks should hold. Transfer the whites to a large mixing bowl.
Alternate folding the dry ingredients and the brown butter into the egg whites, a third of a time. Remember to scrap the bottom of the brown butter pan with a rubber spatula to get all the little brown bits.
Pour the batter into the prepared cake pan, and bake for 50 minutes to 1 hour**. Cool on a rack 30 minutes. Run a knife around the inside edge of the pan, and invert the cake onto a plate. Peel off the paper, and turn the cake back over onto a serving platter. Sprinkle it with powdered sugar or cover with ganache.
* I removed the skins (which are especially tough on the delicious Oregon hazelnuts I found) by toasted them on a baking sheet at 350deg for about 15 minutes then either (I tried both methods) wrapping the warm nuts in a dish towel, letting it steam for five minutes and then vigorously rubbing them together to remove the skins or by plunking them in a colander and using a hard, dry, clean scrub brush to brush their skins off.
** Mine was done at 40 minutes so check yours even earlier, okay?