To prepare cake: Prepare Manischewitz Red Velvet cake according to package directions. Set aside to cool.
To prepare the ice cream: Blend the cream cheese, milk, lemon juice, contents of frosting packet, and salt in a food processor or blender until smooth. Pour into the bowl of an ice cream maker and freeze according to manufacturer’s instructions, about 30 minutes. Enjoy immediately for soft serve or allow to harden a bit longer in the freezer for hard scoop ice cream.
To assemble parfait: Cut cooled cake into small squares. In parfait glasses layer cake with ice cream in alternate layers starting with cake and ending with ice cream. Top with a few crumbled cake squares and freeze or serve immediately.