Creating these Key Lime Pie Bars is a simple process that follows these easy steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Prepare the Crust: In a medium bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Mix until well combined.
3. Form the Crust: Press the mixture evenly into the bottom of a greased 8×8 inch baking dish. Flatten it with the back of a measuring cup or your fingers to create an even layer.
4. Bake the Crust: Place the dish in the preheated oven and bake for about 10 minutes, until slightly golden. Remove from the oven and let it cool.
5. Make the Filling: In a large bowl, whisk together the egg yolks until they’re light in color. Then, add in the sweetened condensed milk and mix until combined.
6. Add Lime Juice and Zest: Gradually add the key lime juice and lime zest to the mixture, stirring gently until everything is well combined.
7. Pour Filling Over Crust: Pour the filling into the cooled crust, spreading it evenly.
8. Bake Again: Return the dish to the oven and bake for another 15-20 minutes, just until the filling is set.
9. Cool the Bars: Remove from the oven and allow the bars to cool at room temperature for about 30 minutes. Then transfer to the refrigerator and chill for at least 1.5 to 2 hours to allow them to set completely.
10. Slice and Serve: Once chilled, cut the bars into squares and, if desired, serve with whipped cream and lime slices for garnishing.

This straightforward method makes it a breeze to enjoy these delicious bars at home!