Servings: 48 bars

Active Work Time: 45 minutes

Total Preparation Time: 1 hour 15 minutes

Note: To blanch (peel) hazelnuts, roast them in a 350-degree oven in a single layer until you can smell them, 10 to 15 minutes. Rub the nuts, a handful at a time, in a towel until the peels fall off. Lift the nuts out carefully, shaking off any flakes of peel. You can find blanched, roasted hazelnuts at some gourmet shops. Be sure the egg whites in the hazelnut layer are at room temperature .

CHOCOLATE LAYER

1 cup unbleached all-purpose flour

1 cup (about 2 1/2 ounces) finely ground toasted blanched hazelnuts

1/2 cup sugar

1/8 teaspoon ground cinnamon

Dash sea salt

1/2 cup (1 stick) unsalted European-style butter

1 egg yolk

1 teaspoon vanilla extract

4 ounces bittersweet or semisweet chocolate, ground to a powder

1. Line the bottom and sides of a 13x9-inch baking pan with one sheet of parchment paper.

2. Blend the flour, hazelnuts, sugar, cinnamon and salt in a mixing bowl. Make a well in the center and cut in the butter in small pieces. Add the yolk and vanilla, then pour the chocolate over all.

3. Blend the ingredients together with your fingertips, then when it becomes a cohesive dough, knead gently into a ball.

4. With a fork or your fingertips, gently smooth the dough so it evenly covers the paper in the pan. Set the dough in the freezer to chill while you make the hazelnut layer.