Frog Eye Salad

This is from my SIL, Brenda. It's not at all complicated, but it's always satisfying.

¼ to ½ box (about 1 cup) Acini de Pepe or ABC pasta, cooked and cooled
1 can mandarin oranges, drained
1 can pineapple tidbits, drained (reserve ¼ c. juice)
8 oz. cool whip
1 small box instant vanilla pudding mix
Miniature marshmallows, optional
        Combine pudding mix with 1/4 c. pineapple juice. Stir in cool whip. Add other ingredients, stir well and refrigerate.