In a medium bowl, whisk together the cream cheese, key lime juice, and sweetened condensed milk. Taste and add more lime juice or sweetened condensed milk to your taste. Optional, stir in a little bit of lime zest – ½ t or so.
Use a fork to mix together the cereal and butter in a small bowl.
Divide cereal mixture into 8 small 3-4 oz dessert cups or other similar small dishes. Adjusting the quantity based on the size of the dish.
Divide the cream cheese mixture on top.
Top with whipped cream and a light sprinkle of lime zest for garnish.