• In a small mixing bowl, mix together the Graham cracker crumbs and melted butter until well combined. Mix with a fork first then your hands until all the crumbs are coated in the butter.
  1 cup Graham crackers crumbs, 4 Tbsp unsalted butter
  
• Divide half of the mixture and place it in an even layer among 4 glasses or dessert cups. You can use your fingers or the bottom of a small measuring cup to press the buttery mixture firmly on the bottom of the cup or glass. 
  
• Start by zesting the lime and then juice the limes using a citrus reamer.
  ¼ cup lime juice, 1 Tbsp lime zest
• Using a hand mixer, beat the cream cheese until smooth. Add the condensed milk, key lime juice, and lime zest, and beat until you have a thick and creamy filling. 
  4 oz cream cheese, ½ cup sweetened condesded milk, ¼ cup lime juice, 1 Tbsp lime zest
• Spoon half of the key lime filling into the glasses on top of the graham cracker crust. Then repeat with the rest of the Graham cracker crumbs, and then with the rest of the filling, to make even layers.
  

Whipping Cream

• Using a hand mixer or in the bowl of an electric mixer fitted with the whisk attachment (or beaters) beat the whipped cream and powdered sugar until medium stiff peaks form. 
  ½ cup heavy whipping cream, 1 Tbsp powdered sugar
  

Chill

• Chill the glasses in the refrigerator for at least 2 hours. When ready to serve, garnish with whipped cream and decorate with a little bit of lime zest.