In a medium bowl, whisk together the condensed milk, Greek yogurt, lime juice, lime zest, salt, and vanilla extract until completely smooth and well combined. The mixture should be homogeneous with no streaks of yogurt visible. This takes about 1-2 minutes of whisking. I like to use a whisk rather than a blender here because it prevents the mixture from becoming too aerated, which keeps the pie denser and more luxurious.

Preheat your oven to 350°F. While the oven heats, pour the filling mixture from Step 1 directly into the prepared graham cracker crust, spreading it evenly with a spatula so it reaches all edges and sits level in the pan.

Place the pie in the preheated oven and bake for 6-8 minutes, until small bubbles just begin to appear on the surface. The filling should still jiggle slightly in the center when you gently shake the pan—this is the correct doneness. The pie will continue to set as it cools, so don't overbake or you'll end up with a denser, less creamy texture. I remove mine as soon as I see the first few bubbles forming because the residual heat does the final setting.

Remove the pie from the oven and let it cool to room temperature on a wire rack for about 30 minutes. Once cooled, transfer it to the refrigerator and chill for at least 3-4 hours, or preferably overnight, until the filling is completely set and chilled through. This resting time is essential for the flavors to meld and for the pie to achieve the perfect creamy texture.