Combine warm water and yeast in a small bowl; set aside for 5 minutes to soften yeast.
Combine milk, butter, sugar and salt; heat until warm (100° to 110°F). Pour into large mixer bowl. Add yeast mixture, eggs and 4 cups flour. Beat for 3 minutes on medium speed until smooth. Gradually add enough remaining flour to make a soft dough.
Knead dough on a lightly floured surface for 8 to 10 minutes, until dough is smooth and elastic. Place dough in a greased bowl, turning once to coat all sides. Cover and place in a warm, draft free place and let rise about 45 to 60 minutes, until doubled in bulk.
While dough is rising, prepare filling. Combine brown sugar, spices and salt in a small bowl. Set aside. Cook bacon until crisp; drain on absorbent toweling. Reserve 2 tablespoons bacon drippings in a small bowl to cool. Crumble bacon when cool enough to handle.
Punch dough down and turn out onto a lightly floured surface. Divide dough in half; roll each half into a 12 x 9-inch rectangle. Brush surface with bacon grease; sprinkle each rectangle with an equal amount of brown sugar mixture and crumbled bacon. Roll up dough, starting from the long side; press seams together to seal. Cut each log into 9 equal slices. Place 9 rolls each (cut side down) in a greased 13 x 9-inch pan. Cover and let rise about 30 to 45 minutes in a warm, draft free place, until doubled.
Bake in a preheated 350°F oven for 18 to 20 minutes, or until lightly browned (internal temperature of rolls should reach 190°F). Let cool 10 minutes in pans; invert on large serving platter or surface covered with parchment paper and frost.
To make frosting, mix powdered sugar and syrup in a medium bowl. Stir in enough milk to reach desired consistency.