Heat oven to 350°F. If using crescent rolls: Unroll dough; separate into 2 long rectangles. Press each into 12x4-inch rectangle, firmly pressing perforations to seal. If using dough sheet: Unroll dough; cut lengthwise into 2 long rectangles. Press each into 12x4-inch rectangle.
Spread dressing over each rectangle to edges. Sprinkle each with bacon, Cheddar cheese and onions. Starting with one short side, roll up each rectangle; press edge to seal. With serrated knife, cut each roll into 8 slices; place cut side down on ungreased cookie sheet.
Bake 12 to 17 minutes or until edges are deep golden brown. Immediately remove from cookie sheet. Serve warm.