1In 12-inch nonstick skillet, cook 1/4 cup of the pancetta over medium-low heat 4 minutes or until golden brown and crisp. Remove pancetta to paper towels to drain; reserve drippings in skillet. Cook bread cubes in drippings 7 minutes, stirring frequently, until golden and crisp. Stir in rosemary; cook 1 minute. Return pancetta to skillet. Remove from heat; set aside.
2In 4-quart Dutch oven, cook remaining pancetta over medium-low heat 4 minutes or until golden brown and crisp. Add onions; cook 5 minutes, stirring occasionally. Add sweet potatoes, milk, water, pepper and salt. Heat to boiling; reduce heat. Cover; simmer 15 minutes.
3In blender or food processor, place 3 cups soup. Cover; blend until smooth. Pour blended soup into large bowl; cover to keep warm. Repeat procedure with remaining soup. Sprinkle individual servings with croutons.