Chill a 9-by-5-inch metal loaf pan in the freezer for 20 minutes.
Meanwhile, combine the cream and cereal in a medium bowl and allow to steep for 20 minutes. Strain the mixture through a fine-mesh sieve, pressing on the solids to extract as much cream as possible (you should have about 2 cups). Discard the cereal.
Pour the sweetened condensed milk into a large bowl and set aside.
Whip the cereal cream with an electric mixer until stiff peaks form. Gently fold the whipped cream into the sweetened condensed milk until smooth and well combined and transfer to the chilled loaf pan. Cover with plastic and freeze until firm, at least 4 hours and up to overnight.