1 (20 oz.) can pineapple tidbits, drained and juice saved
2 c. small marshmallows
1 1/2 tbsp. vinegar
1/2 c. sugar
1 egg, beaten
1 tbsp. flour
2-3 c. unpeeled, diced apples
1 1/2 c. salted peanuts
1 (12 oz.) tub Cool Whip

Mix pineapple tidbits and marshmallows together; cover and refrigerate. Stir together vinegar, sugar, egg and flour and cook until thick. Let dressing mixture cool. Add diced apples to large mixing bowl. Stir in pineapple mixture and cooled dressing. Stir in peanuts and Cool Whip.