Soten gelatin in water for 5 minutes. Cream butter and sugar until light and fluffy. Blend in the egg yolks well. Cook over low heat,stirring constantly until thickened. Remove from heat, add gelatin and stir until dissolved.
Cool slightly then add marshmallows. Blend lightly and chill until mixture begins to thicken. Fold in peaches and beaten egg whites.
Arrange alternate layers of cookie crumbsand peach filling in mold,beginning and ending with cookie crumbs.
Chill until firm. Unmold and serve with whipped and sweetened cream.