Dissolve yeast in warm water in a large bowl; let stand 5 minutes.
Lightly spoon whole wheat flour into dry measuring cups; level with a knife. Add whole wheat flour, honey, oil, molasses, and salt to yeast mixture, stirring well to combine. Cover and let stand at room temperature 1 hour to create a sponge.
Add wheat germ and cornmeal to sponge. Lightly spoon bread flour into dry measuring cups; level with a knife. Add 1 cup flour to sponge; stir until a soft dough forms. Turn dough out onto a floured surface. Knead until smooth and elastic (about 8 minutes); add enough of remaining flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel tacky). Knead in sunflower seeds and blueberries.
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in size. (Gently press 2 fingers into dough. If indentation remains, dough has risen enough.)
Punch dough down. Cover and let rest 5 minutes. Roll into a 14 x 7-inch rectangle on a floured surface. Roll up tightly, starting with a short edge, pressing firmly to eliminate air pockets; pinch seam and ends to seal. Place roll, seam side down, in an 8 x 4-inch loaf pan coated with cooking spray. Coat dough with cooking spray. Cover and let rise 45 minutes or until doubled in size.
Preheat oven to 375°.
Uncover dough; bake at 375° for 45 minutes or until loaf is browned on bottom and sounds hollow when tapped. Remove from pan; cool on a wire rack.