In a small bowl, combine spices, mixing well; set aside. In a large mixer bowl, dissolve yeast in water. Stir in 1/2 cup sugar, 6 tablespoons butter, salt, dry milk and pumpkin. Add 2 teaspoons of spice mixture and 2-1/2 cups flour. Beat on low speed 3 minutes, scraping bowl often. Gradually beat in enough remaining flour, about 2-1/2 cups, to form a stiff dough. On lightly floured surface, knead until smooth, adding flour as needed. Place in greased bowl, turning to grease top. Cover; let rise in warm place until double in volume, about 1-1/2 hours.
Lightly grease a 10-inch tube pan; if pan has removable bottom, line the bottom and sides with foil. Combine remaining spice mixture and 1 cup sugar; mix well. Punch down dough; divide into thirds. Shape each third into a smooth 18-inch rope; cut each into 18 equal pieces. Shape pieces into smooth balls. Dip each ball in remaining melted butter and roll in sugar mixture. Arrange 18 balls in a single layer in bottom of pan so they just touch; sprinkle with one-third of the nuts. Top with two remaining layers of 18 balls each, staggering balls; sprinkle each layer with remaining nuts. Cover pan lightly; let rise in warm place until balls double in size, about 45 minutes. Preheat oven to 325 °F. Bake 70 minutes, or until golden brown. Cool on wire rack 20 minutes; invert onto serving plate. To serve break apart with forks.