Pour boiling water over 1/2 cup fiber cereal. Let stand for about three minutes. Drain and press out excess water. Sprinkle yeast, in a bowl of lukewarm water and honey. Let stand until foamy, about three minutes. Add butter, salt, and two cups of the white flour. With electric mixer or by hand, beat until the consistency of thick cake batter, about two minutes. Gradually mix in remaining flours 1/2 a cup at a time and soaked cereal. With heavy duty mixer, or by hand, knead until dough is smooth and elastic, about 8 minutes by hand. Place in greased bowl, turn to coat the entire ball, cover with a damp cloth or plastic wrap, and let rise until double in bulk, about 45 minute. Punch down and turn out onto lightly floured surface. Sprinkle dough with ½ cup hazelnuts. Gently knead the nuts into the dough. Divide dough into two pieces. Form the dough into two discs that are about eight inches in diameter and one inch thick. Place on greased baking sheets. Cover with oiled plastic wrap, and let rise until a slight indentation remains when lightly pressed with fingertips, about 45 minutes. Shortly before baking time, position a baking rack in the center of the oven and heat the oven to 375 degrees. Brush the tops of the loaves with Egg Yolk Glaze and sprinkle with remaining cracked wheat and hazelnuts. Bake on the center rack of a 375-degree oven for about 30 to 35 minutes. Cool on rack.
