2Using kitchen scissors or paring knife, cut each marshmallow into 4-6 pieces into a large mixing bowl (DO NOT use miniature marshmallows, it won't work; this step is sticky and a little tedious, but the results are so worth it!) Set aside.
3In a mixing bowl, whip cream to stiff peak stage and set aside.
4In a small saucepan, mix together well, egg yolks, sugar and vinegar.
5Cook, stirring constantly, over medium/medium low heat until just thickened.
6Remove from heat, add pineapple and stir until coated.
7Pour mixture over marshmallows and mix very well (until all the marshmallow pieces are coated.)
8Add whipped cream and fold in well.
9Cover and refrigerate.
10Before serving, give it an additional stir for final blending of flavors.