Butter a piece of brown paper cut to fit a large cookie sheet. Preheat to moderate (375 degrees). Sift flour, sugar and baking powder into a large bowl; stir in cake crumbs. Beat eggs, the egg yolk, almond extract and vanilla in a small bowl until frothy; add to flour mixture. Beat unti thoroughly combined and mixture is moistened. (Take a little bit of the cookie mixture between your fingertips and pinch; if the dough holds together you have beaten it enough). Add almonds and hazelnuts. WIth your hands, work nuts into dough until mixture begins to hold together. Turn out onto a piece of wax paper. Divide mixture in half. Shape each half into a log, 2 inches in diameter and about 12 inches long. Place logs on prepared cookie sheets. Beat egg white in a small cup until foamy; brush over logs. Bake in preheated 375 degree oven for 30 minutes or until golden. Remove logs with paper to wire racks. Cool 1 hour. Preheat oven to 350 degrees. Cut logs into 1/2 diagonal slices with a serrated knife using a sawing motion. Place cookies on large ungreased cookie sheets. Bake in preheated moderate oven (350 degrees) for 10 minutes or until centers are dry, turning once. Cool on wire racks. Store in a covered container ----