Preheat oven to 375°.

Toast almonds until they turn a light golden color. Cool. Grind 1/2 cup of the almonds fine. Toast hazelnuts on sheet pan until skins crack. Remove and place in a towel and rub off the skins as much as possible. Chop coarsely.

Reduce oven temperature to 350°.

Butter cookie sheets. Combine and sift flour, baking powder and cinnamon. Add all the almonds and hazelnuts. In a large bowl whisk eggs until frothy. Add butter and sugar and mix until combined. Add flour-nut mixture. The dough will be rather sticky. Shape four 12-inch by 2-1/2-inch logs. Place four inches apart on cookie sheets. Smooth tops.

Bake 25 minutes or until firm when pressed in the center. Gently slide logs off the pans and cut them diagonally into 1/2-inch slices. Stand the pieces up right on the cookie sheets. Return to oven and bake 20 minutes longer, until crisp and brown. Let cool on a wire rack.