Cook squash in a saucepan of boiling salted water for 3 minutes. Add the tortellni; cook according to package directions and until squash is tender. Drain.
Heat oil in a skillet over medium high heat. Add prosciutto, cook untilcrisp, then drain on a paper towel=lined plate. Return skillet to burner (with drippings still in pan); reduce heat to medium.
Melt butter in the skillet. Add sage sprig and cook until butter brown, about 4 minutes; remove sage and discard. Stir in wine and sugar; cook 30 seconds, then add reserved squash, tortellini, and prosciutto back into pan. Toss to heat through.
Off heat, finish with lemon juice, parsley, and pepper.