2 1/2 cups warm water (110 degrees F)
1 (18.25 ounce) package yellow cake mix
6 cups all-purpose flour, divided
1/3 cup vegetable oil
1 1/2 teaspoons salt
1/2 cup butter, softened
4 tablespoons white sugar
2 tablespoons ground cinnamon
1/4 cup butter, melted
3 cups confectioners' sugar
1 1/2 teaspoons vanilla extract
2/3 cup milk
1 In a large bowl, dissolve yeast in warm water, and let stand for 3 minutes. Add cake mix, 1 cup flour, eggs, oil, and salt; beat well. Stir in remaining flour until a soft dough forms.
2 Knead on well floured surface for about 5 minutes. Place in a greased bowl, and turn to coat the dough surface. Let rise until doubled in bulk, about 45 minutes.
3 Preheat oven to 350 degrees F (175 degrees C).
4 Punch down, and divide into two equal parts. Roll out each section on a lightly floured surface. Spread each with softened butter and sprinkle with sugar and cinnamon.
5 Roll up like jelly rolls and cut buns 1 1/2 inches thick with a piece of dental floss or a dull knife. Place in greased baking pans, and allow to rise until doubled.
6 Bake at 350 degrees F (175 degrees C) for 25 to 35 minutes or until golden brown.
7 Meanwhile, combine confectioners sugar, 1/4 cup melted butter, vanilla, and milk. Remove baked buns from oven and drizzle with frosting.