In a large bowl, dissolve yeast in warm water. Add warm milk, buttermilk, sugar, butter, salt and 4 cups flour. Beat on medium speed until smooth. Stir in enough remaining flour to form a soft dough (dough will be sticky)., 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 in a warm place until doubled, about 1 hour., Punch dough down; turn onto a floured surface. Roll into an 18x12-in. rectangle; brush with butter. Combine brown sugar, coffee granules and cinnamon; sprinkle over dough to within 1/2 in. of edges., Roll up jelly-roll style, starting with a long side; pinch seam to seal. Cut into 12 slices. Place rolls, cut side down, in a greased 13x9-in. baking pan. Cover and let rise until doubled, about 30 minutes., Preheat oven to 350°. Bake 22-28 minutes or until golden brown. Place pan on a wire rack. In a small bowl, beat icing ingredients until smooth. Spread over rolls. Serve warm.