Warm the milk, brown sugar, 4 tablespoons of the butter, and salt in a small saucepan to 110ºF to 115ºF; set aside.
In the bowl of an electric mixer (or using a large bowl), dissolve the active dry yeast in warm water (water should also be about 110ºF to 115ºF). Stir in the milk mixture.
Add 1 1/2 cups flour, all of the whole wheat flour, pumpkin, and pumpkin pie spice to the electric mixer bowl. Using the dough hook mix the ingredients on low until a soft dough is formed. If the dough is still too sticky add the remaining flour.
Increase the speed to medium and continue to knead the dough for 5 to 7 minutes until it's smooth and slightly sticky. Spray a large glass bowl with cooking oil and place the dough in it turning it over to coat all sides. Cover and place in a warm place to let rise and double in size, about 1 hour (If kneading by hand turn the dough out onto a floured surface and knead until smooth, about 6 to 8 minutes).
Punch the dough down and divide into 15 pieces. Shape into balls by making a c-shape with your hand and rolling the dough on a hard flat surface.
Place the prepared dough balls into a greased 13x9-inch baking pan, cover and let rise for 30 minutes or until doubled.
Preheat the oven to 375ºF. Melt the remaining butter and brush over the tops of the rolls. Bake for 20 to 25 minutes or until golden brown. Remove and let cool for about 15 minutes before serving.