In the bowl of a stand mixer, combine yeast, one cup flour, oats, cinnamon and salt.
In a large measuring cup (or small bowl), combine water, oil and brown sugar. Heat to 120-130° F (about 1 minute in microwave at high power). Use instant read thermometer to test the temperature.
Add liquid ingredients to the dry mixture in the mixing bowl. Using paddle attachment, beat on low speed (#2) for 4 minutes.
Add remaining 1 ½ cups flour to the mixing bowl. Switch attachment to dough hook. Knead for 6 minutes on low speed (#2), or until dough is smooth and elastic. If dough seems too stiff (the mixer is working too hard), add water, 1 tablespoon at a time.
After 6 minutes, add the cranberries and walnuts to the bowl. Turn the mixer on low speed to incorporate them into the dough. If some remain in the bowl, take the dough and remaining cranberries/nuts out of the bowl and knead lightly until they are incorporated.
Place dough in a lightly oiled bowl, turn to grease dough. Cover and let rise in a warm place until dough doubles in size, about 1 hour (see note).
Remove dough from bowl and form into a rectangle, approximately 7 x 14 inches. Starting with the short side, roll up tightly to form a tight roll. Place in a greased 9 x 5-inch loaf pan. Cover with a clean towel and let rise until doubled, about 1 hour.
Preheat oven to 375°F with rack in middle of oven. Bake bread for 40 to 45 minutes or until internal temperature is 190°F.
Cool 10 minutes on wire rack, remove loaf from pan, and cool completely on wire rack before slicing. If desired, brush the top of the warm loaf with melted butter.
Notes
Use rolled oats (old-fashioned) or quick oats. Do not substitute instant oatmeal or steel cut oats.
Don’t have a warm spot in your kitchen? Some newer model ovens have a “Proofing” setting which is made for this purpose. This short YouTube video will show you another good method.
If you prefer, substitute raisins or dried cherries for the cranberries.
Nut Free: Omit walnuts. Use pepitas (shelled pumpkin seeds) or sunflower seeds instead.