Heat oven to 375°F In 10-inch nonstick skillet, cook bacon over medium heat 2 minutes. Add ground beef and onion; cook, stirring occasionally, until beef is thoroughly cooked; drain if necessary. Stir in pickles and ranch dressing.
Unroll dough and separate each can into 4 rectangles; place on ungreased cookie sheet. Press each into 7 x 4-inch rectangle, firmly pressing perforations to seal.
Spoon about 1/3 cup ground beef mixture onto one end of each rectangle. Top each with tomato slices and 1 piece of cheese. Fold dough over filling; press edges with fork to seal (sandwiches will be full). Brush tops with egg.
Bake 15 to 20 minutes or until deep golden brown. Immediately remove from cookie sheet. Serve warm.