In a large skillet, cook bacon and onion over medium heat until bacon is crisp. Remove with a slotted spoon; drain on paper towels. Cool slightly., In a small bowl, mix sour cream, cheese and bacon mixture. On 2 greased baking sheets, roll each dough into a 16x10-in. rectangle. Spoon half the filling lengthwise down center third of each rectangle., On each long side, cut 3/4-in.-wide strips about 2-1/2 in. into the center. Starting at 1 end, fold alternating strips at an angle across filling. Pinch both ends to seal., Cover with kitchen towels; let rise in a warm place until doubled, about 1 hour. Preheat oven to 350°., Brush loaves with egg; sprinkle with parsley and poppy seeds. Bake until golden brown, 25-30 minutes. Remove from pans to wire racks.