The recipes I have seen for the southern Ambrosia do not have creamy dressings, but what I think you might be looking for is what my Mom called 24 Hour Salad. Christmas wouldn't have been Christmas without it, it is as delicious as it is rich. Let me know if this sounds right.

24 HOUR FRUIT SALAD

FOR THE DRESSING:
3 egg yolks
2 Tablespoons sugar
1/8 teaspoon salt
2 Tablespoons vinegar
2 Tablespoons Pineapple syrup
1 Tablespoon butter
1 cup heavy cream, whipped

Beat egg yolks slightly with a fork. Add sugar, salt, vinegar, pineapple syrup and butter and cook in small saucepan over low heat until thick, stirring constantly. Cool. Fold in whipped cream.

FOR THE SALAD:
2 cups (1 can) pitted drained white cherries (I usually use the purple bing cherries)
2 cups (about 20 oz can)pineapple tidbits, drained, reserve 2 Tablespoons syrup for above dressing
2 cups miniature marshmallows
2 oranges, peeled, sectioned, and cut in bite-sized pieces

Place above ingredients in a large bowl, and fold in the dressing. Chill 24 hours.