With three ingredients.
Compare this slight more elaborate version from the May 18, 1933 edition of The Iola (Kansas) Daily Register:
Marshmallow Ice Cream.
1 cup milk
Add marshmallows to milk and melt in double boiler; chill until slightly thickened. Whip cream, add almond and salt and beat into cold mixture. Turn into freezing tray and freeze three to four hours. Fills one pint tray.
From the box of G.Y. from Wichita, Kansas.
Marshmallow Ice Cream
2 cups milk
1 cup whipping cream
Melt marshmallows in hot milk in double boiler, stirring occasionally, and cool. Fold in candy and cream until just holds shape; pour in tray–place in freezing unit. Set control at highest point to freeze.
When mushy, stir three times with fork at 15 minute intervals. When frozen, set control back to temperature slightly colder than ordinary maintained to let mixture [soften?].
Serves 6 to 8.