Preheat your oven to 325°F.
Line a standard muffin tin with paper liners.
Combine graham cracker crumbs, 2 tbsp sugar, and melted butter until moist.
Press 1 tbsp of the mixture into the bottom of each muffin liner.
Bake the crusts for 5 minutes and remove to cool slightly.
Beat the softened cream cheese with the remaining sugar until smooth.
Add the eggs one at a time, followed by the key lime juice and vanilla extract.
Pour the filling over the prepared crusts in the muffin tin.
Bake for 15 minutes or until just set.
Cool to room temperature then refrigerate for at least 3 hours before serving.