Combine cake mix, 1 cup flour and yeast. Add water; beat on medium speed 2 minutes.
Stir in enough remaining flour to form a soft dough (dough will be sticky).
Turn onto a lightly floured surface; knead gently 6-8 times. Place in a greased bowl, turning once to grease the top. Cover and let rise in a warm place until doubled, about 2 hours.
Meanwhile, in another bowl, mix brown sugar and cinnamon.
Punch down dough. Turn onto a lightly floured surface; roll dough into an 18x10-in. rectangle.
Brush with melted butter to within 1/4 in. of edges; sprinkle with sugar mixture.
Roll up jelly-roll style, starting with a long side; pinch seam to seal. Cut crosswise into 12 slices.
Place cut sides up in a greased 13x9-in. baking pan. Cover with a kitchen towel; let rise in a warm place until almost doubled, about 1 hour.
Preheat oven to 350°. Bake until puffed and light brown, 15-20 minutes. Cool slightly.
Beat confectioners’ sugar, butter, vanilla and enough milk to reach a drizzling consistency. Drizzle icing over warm rolls.
