Melt the Butter: In a large saucepan, melt the butter over low heat.

Add the Marshmallows: Stir in the marshmallows and continue to stir until completely melted and smooth.

Mix in Rice Krispies: Remove the pan from heat and stir in the Rice Krispies cereal, mixing gently until everything is evenly coated with the marshmallow mixture.

Press into a Pan: Transfer the mixture to a greased 9×13-inch baking dish. Use a spatula or wax paper to press the mixture evenly into the dish. Allow it to cool for 30 minutes.

Cut into Squares: Once the Rice Krispie mixture has cooled, cut it into squares or rectangles, depending on the size you want for your ice cream sandwiches.

Add Ice Cream: Let the vanilla ice cream soften for about 10 minutes before scooping it onto a Rice Krispie square. Place another square on top to form a sandwich.

Freeze the Sandwiches: Arrange the sandwiches on a baking sheet and freeze them for at least 2 hours, or until they are firm and hold together well.

Serve and Enjoy: Once frozen, the sandwiches are ready to serve! Enjoy them right away or store them in the freezer for later.