01 - Combine mashed bananas, whole milk, heavy cream, sweetened condensed milk, granulated sugar, vanilla extract, and salt in a blender. Blend until completely smooth.
02 - Pour blended mixture into Ninja Creami pint container, seal, and freeze upright for a minimum of 12 hours.
03 - Mix graham cracker crumbs with melted unsalted butter and brown sugar in a small bowl until the mixture resembles wet sand. Set aside.
04 - Insert frozen pint into Ninja Creami and process using the Ice Cream setting.
05 - After the first spin, create a one-inch well in the center of the ice cream. Add the prepared graham cracker crumble.
06 - Reinsert the pint and process using the Mix-In function until the graham cracker mixture is fully incorporated.
07 - Scoop ice cream into bowls and top with whipped cream and sliced bananas as desired. Serve immediately.