Preheat oven to 350 degrees F.
Prepare 8x8-inch pan by lining it with aluminum foil, set aside.
Add crust ingredients to a medium mixing bowl and mix until combined.
Press into even layer on bottom of prepared pan. Bake for 8 minutes, then cool while preparing the filling.
Add cream cheese, vanilla extract, lime juice, and lime zest into a bowl of a stand mixer or medium mixing bowl if using a hand mixer. Beat 2 minutes on medium-high speed, will be runny.
Beat in condensed milk, about 2 minutes medium speed until combined.
Then mix in egg yolks by hand, one-two at a time.
Pour filling over baked crust.
Place in oven and bake for 15 minutes or until filling is just set. Allow to cool, then refrigerate for at least 2 hours to overnight.
Cut and serve with a dollop of whipped cream, a sprinkle of lime zest, and a key lime slice if desired.