Place egg whites in a large bowl; let stand at room temperature for 30 minutes. Add cream of tartar; beat on medium speed until foamy. Add vinegar and vanilla; beat until soft peaks form. Gradually beat in sugar, 1 tablespoon at a time, on high until stiff glossy peaks form and sugar is dissolved.
Spread evenly into a greased 13x9-in. baking dish. Bake at 225° for 1-1/4 hours; turn off oven and do not open door. Let meringue dry in oven for 1 hour.
In a large bowl, beat the cream cheese, sugar and vanilla until smooth; gently fold in whipped cream and marshmallows. Spread over meringue. Cover and chill for 12 hours.
Cut into squares; top with pie filling and strawberries. Refrigerate leftovers.