In bowl dissolve yeast in ½ cup warm, water. Beat together egg, 2-½ cups warm water, butter, maple syrup, and salt. Stir in yeast and whole-wheat flour. Then add unbleached flour and walnuts. Cover with cloth. Let rise for 1 hour on stove top or warm place. Remove dough and divide into 5 equal parts. Sprinkle sesame seeds on counter and knead into dough. Place in 5 greased and floured 1-pound coffee cans. Bake at 350 degrees F for 45 minutes. Remove from oven and take bread out of cans as soon as it shrinks (about 15 minutes).