In a large bowl, combine 1-1/2 cups flour, oats, brown sugar, salt and yeast. In a saucepan, heat milk and shortening to 120°-130°. Add to the oat mixture; mix well. Add eggs, one at a time, beating well after each. Add enough remaining flour to form a stiff dough. Turn onto a floured surface; knead until smooth and elastic, about 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and let rise until doubled, about 1 hour.
Punch dough down. Roll into a 16x12-in. rectangle. Combine filling ingredients; sprinkle over dough to within 1/2 in. of edges. Roll up jelly-roll style, starting with a long side. Cut into 12 slices.
Sprinkle nuts into a greased 13x9-in. baking pan. Combine the remaining topping ingredients; pour over nuts. Place rolls over topping. Cover and let rise for 30 minutes. Bake at 350° for 30-35 minutes or until golden brown. Cool for 5 minutes before inverting rolls onto a wire rack.