Preheat your oven to 350°F (175°C). Combine graham cracker crumbs, melted unsalted butter, and granulated sugar. Spread on a baking sheet and bake for 5-6 minutes, or until golden brown. Allow to cool.

In a mixing bowl, beat the softened cream cheese until smooth. Gradually add sweetened condensed milk, then key lime juice and zest, blending until smooth.

Chill a mixing bowl for 10 minutes. Pour in the cold heavy cream and whip on high speed until stiff peaks form. Add confectioners' sugar during the last minute.

Layer the shooters by starting with a spoonful of graham cracker crumbs, followed by key lime filling, and repeat until full, leaving room for whipped cream.

Spoon whipped cream on top of each shooter and garnish with key lime wheels or zest curls.

Serve immediately or chill in the fridge for about 30 minutes before serving. Can be prepared up to 24 hours in advance.