Dissolve yeast and maple syrup in warm water in a large bowl; let stand 5 minutes. Add 2 cups flour, cornmeal, and next 2 ingredients; beat at medium speed of a mixer until blended. Stir in 3/4 cup flour to form a soft dough, and turn out onto a lightly 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.
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 bulk. Punch dough down, and roll into a 14 x 7-inch rectangle on a lightly floured surface. Roll up tightly, starting at short side, pressing firmly to eliminate air pockets; pinch seam and ends to seal. Place roll, seam side down, in an 8 1/2 x 4 1/2-inch loaf pan coated with cooking spray. Cover and let rise 1 hour or until doubled in bulk.
Combine 2 teaspoons water and egg white, and gently brush over dough. Bake at 375° for 35 minutes or until loaf sounds hollow when tapped. Remove from pan; let cool on a wire rack.