3 tablespoons of unsalted butter.
1 teaspoon of vanilla.
½ cup of whole hazelnuts.
½ cup of light brown sugar, firmly packed.
1/3 cup of all-purpose flour.
3 large egg whites.
¼ teaspoon of salt.
2 medium plums, thinly sliced.
1 ½ teaspoons of granulated sugar.
Preheat your oven to 425°F (220°C). Butter and flour an eight-inch round cake pan, knocking out excess flour. In a saucepan, melt the butter over moderate heat and allow to cool. Stir in the vanilla. In a food processor blend together the hazelnuts, brown sugar and flour until the nuts are finely ground. In a bowl, beat the egg whites with salt using an electric until they hold stiff peaks. Gently fold in the nut mixture. Fold in the butter mixture (batter will deflate) and spread batter in your prepared pan. Arrange the slices of plum evenly over the batter and sprinkle with the granulated sugar. Bake the cake in middle of your oven for 22 minutes, or until a tester comes out clean. Turn cake out onto a rack and allow to cool, plum side up, for 5 minutes. Sift confectioner's sugar onto cake. Serve warm with vanilla ice cream.
