Combine first 5 ingredients in a large bowl. Let stand 5 minutes. Stir in potatoes and oil.
Lightly spoon flour into dry measuring cups; level with a knife. Add 2 cups flour to potato mixture; stir until a soft dough forms. Turn dough out onto a floured surface. Knead dough until smooth and elastic (about 10 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, 55 minutes or until doubled in size. (Gently press two fingers into dough. If indentation remains, the dough has risen enough.)
Punch dough down. Let rest 5 minutes. Roll into a 14 x 7-inch rectangle on a lightly 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 35 minutes or until doubled in size.
Preheat oven to 350°.
Uncover dough. Bake at 350° for 30 minutes or until loaf is browned on top and sounds hollow when tapped. Remove loaf from pan. Cool on a wire rack 15 minutes.