Preheat oven to 350F. Coat 9" x 9" pan with cooking spray. Set aside.

To make the crust, combine graham cracker crumbs, sugar and melted butter. Mix until combined, it will resemble wet sand. Press into the bottom of the prepared pan. Bake for 10 minutes, then remove from oven. 

While the crust is baking, beat cream cheese in the bowl a standing mixer fitted with the paddle attachment set to medium speed. Once it is smooth and creamy add the condensed milk and mix until combined. Add egg yolks one at a time, mixing between each addition. Use a rubber spatula to scrape the sides and bottom of the bowl if needed. Mix in lime juice and vanilla extract until combined. 

Pour over the warm, baked crust and bake for 15 – 20 minutes, until set and the edges begin to brown. Remove from oven and let cool to room temperature, then place in refrigerator to chill for at least 2 hours or overnight. 

Cute and serve! You could top it with whipped cream if you'd like!