Remove orange peel and white pith; cut flesh bite-size over a bowl.

Drain oranges and pineapple in a colander 10 minutes to avoid watery dressing.

Whip cream, powdered sugar, and vanilla to soft peaks.

Fold oranges, pineapple, coconut, marshmallows, and pecans into cream just to coat.

Refrigerate 1 hour; serve within 6 hours while fruit retains texture.